OK, Thunder, you obviously haven't been keeping track of the SCP. Almost all of these can be implemented in one form or another, and some searching would have helped you make more informed requests. I'm gonna go over each one with what I know.
1: FRED2 Ambient Lighting Slider
A slider in the FRED2 mission options section that determins the amount of ambient light in a mission. Everything will be affected by this light with the exception of the HUD and the Jump Nodes (which are HUD generated). Useful for specific space where lighting is brighter (a nebula with a newly formed sun in it etc.) or darker.
Fantastic idea.
Should be looked into.
2: All Missile Models Selectable
This could be useful for any number of reasons, none strikingly important but I doubt it would be hard to do. Could provide some pretty cool screenshots, and better show off the missile models (which are so rarely seen).
I don't understand; do you mean targetable, or what?
3: FRED2 Sun Intensity Slider
Similar to point 1, but with the advantage of controlable light without the need for different suns. That is to say that one sun could be brighter than another, and so its light would be brighter - and thus appear more towards that hue than the hue of the dimmer sun. Or, a sun could be present without massively blinding players and screwing up the lighting on ships in the game by having so many light sources present.
Not necessary, IMO. How often are you going to be using multiple suns?
4: Moveable Ship Sections
These would be really cool, for both player operated and automatic purposes. The first instance being for such things as the S-Foils on an X-Wing or for missile bay doors and such. The second being for weapons that feature recoil style firing (similar to the AA guns of WW2, or the station pulse defences on Babylon 5). Also good for landing bays and such on larger ships, or the seemingly movable "claws" of a Sathanas. The possibilities are endless. This would be an immense improvement but would require a new POF version number and huge amounts of rewriting both model handling code and POF data. It's possible but far off in the future.
5: Pulsating Glow Mapping
Take your average glow map and make it pulse at a rate (determined by .TBL file?). Good for bio-tech ships, ships with failing power and so on (see the ending FS2 movie as the Sathani' power up their supernova weaponry). I'd really like to see this make it in.
Easy to do; glowmaps support ANIs. I've made a pulsating Sathanas glowmap ANI that does just what you're talking about.
6: In Game HUD Movies
Allows a window to open in the center of the screen displaying a movie, similar in essence to a COMM window but with the impression of relaying "live feed" of gun camera footage, probe data, or update a players orders mid-battle without resorting to red-alert missions and such.
This can be done if you take the trouble to make your own comm window animations.
7: Expendable After Burners
Ever played Wing Commander Prophecy and flown the Wasp? Then you'll know about expendable "super afterburner" it carries. A one shot rocket device for fast intercept purposes. Would be great for intercept missions and so on, but with the added strategy of only having it once as opposed to the rechargable standard burner.
Simple. Set your ship's afterburner recharge rate to zero. You start the mission with it full; once it's used up you're out of luck.
8: Sequential Lights
Go look at a plane in flight at night. It's got lights that blink on / off. Why not do that for FS? It'd look fantastic. Also, this could be put to use with landing strips as well as nav bouys and so on.
Poke around with the glowpoint code, I think you'll like what you find.
9: Unstable Subspace Flight (etc)
Subspace seems deeply un-used. If I had my way it'd carry the same sort of threat as Babylon5s Hyperspace does. To aid this a start would be such things as unstable jump nodes, the allowance for lightning in normal space as well as in nebulas (and thus in subspace as well... it'd be very creepy). Anything that can be done to jazz subspace up a bit and point out that it's just as strategically vital a place as real space is (heck, the last FS mission sees you fight inside subspace). Something
very cool would be to have the same lightning storm paramaters avaliable in subspace missions as nebula missions.
10: Light Source Blinding
When you face the sun you get a white out of the screen, why not also see this effect when flying to close to ships engines or other bright light sources such as firing beam cannons and such. This would only be a local effect so you'd have to be close, but it's still a small change that'd make sense. Hm, some lens flares might be nice here. But the effect would have to be used selectively or else you wouldn't be able to see anything at all.
11: Smoke Emissions
I imagine this can be done via the particle code we already have. But one of the things I loved about Starlancer was the intense damage you could do to a fighter and really see it. Fires and smoke started in abundance and you really knew if you were in trouble when you started smoking. This would be great in FS2... the same smoke could also be used for vents and such, perhaps for cooling purposes etc... whatever takes a persons fancy.
I don't know what the status of the particle code is, but you already have streams of fire gushing out from damaged fighters. What WOULD be nice is to have the effect scaled up for capital ships (bigger gushers of flames) and to have the particles fade into smoke instead of just cooling off and dissapating. Some new particle ANIs and table tweaks could make the latter possible without any code changes.
12: Red Out / Black Out
This is one of those things that people might hate... but if you've played a flight game it does add a certain something to the way people have to fight. High G maneuvers cause red outs / black outs. Granted FS2 is set in the future and might have guards against this, but perhaps it'd be cool none the less. The code for the screen fade is already there in the sun-glare code, it'd just be a case of applying it if/when a player does a particularly extreme maneuver. I like the idea of a ship's performance being limited by the pilot's capability, but this is definitely beyond the scope of the FS gameplay. I can't think of any easy way to activate or deactivate this without changing the gameplay at a fundimental level.
13: Chargeable Primary Weapons
What better example than Descents Fusion Cannon? The longer you hold down the primary fire, the more charged the weapon becomes and thus the more powerful. Release trigger to fire. Overcharging results in damage to the players own ship. Simple, effective, fun. Yes. Coders ought to look into this.
AFAIK you should be able to peer into the original Descent source code and adapt that.
14: Newtonian Physics
Don't panic. This needn't be complete newtonian physics. A toggle could be added for "free flight", that is the ship can turn in any direction but continue to move in the direction it was originally facing when the toggle was turned on. This allows for many B5 style "turning round and shooting the face of the guy persuing you" type stuff. Just make sure the AI doesn't use it 
If I remember correctly from the FS1 table comments, you can set the deceleration values for all ships to 0 so the only way you'd be able to stop is to turn around and thrust in the opposite direction.
That means that you wouldn't be able to change direction of your own
Volition; that would be an
Outrage! *groan*
15: Partial Repairing of Hulls W/ Welding Effect
Two things here really, support ships able to repair a players ships hull slightly (a random amount between 5 and 30%?) But no more than that for the entire mission... it's a support ship after all - not a repair facility. Also, if this is taking place a welding effect could be created.. perhaps similar to when a ship has taken critical damage - but red - (you know, the lightning arc effect). Not to sure about this though...There is a flag for support ships to repair hulls, but a box next to it enabling FREDders to specify a certain threshold of repair sounds like a great idea. The welding effect I think is confusing and unnecessary.
16: Rail Guns
See Quake3 I guess... the trail should certainly be similar and fade after a matter of seconds.
Can be done by giving a primary weapon a high speed and a long missle smoke trail. This has been avaliable since FS1; see the Port's Railgun for an example.
17: Fire Support
Again, not to sure about this. A comm option allows the player to request fire support - all ships without a current target will direct as much fire as they can on the selected hostile target. Note that they won't change their current orders or alter course (unless they are fighters/bombers without orders). Everybody complains that TAG missiles are useless, yet we get requests like this...
18: Area Effect Mines
Allows the creation of mine weapons - any ship detected withing a .tbl set distance (perhaps 2K) around an armed mine will cause the detonation of the mine. A nice extension of the flak code could create a new proximity detonate flag for weapons; they would explode if a hostile was within a certain radius of the projectile, like flak, and not on impact. Lots of possibilities here.
19: Subsystems Damaged Locally
If a subsystem is disabled/destroyed then the area of the subsystem will give off electrical arcs similar to when the entire hull is critically damaged. Pretty aesthetic, but who cares. Could be interesting, but limiting the electrical arc would be a very difficult task for coders. Probably not worth the effort.
20: HUD Damage
If a players subsystem is hit by energy draining weapons such as EMPs, or if it is destroyed, then the system will blink offline - that is it will simply disappear from the HUD all together untill the system is repaired. FS2 already has a better system. Should you have damaged comms, incoming transmissions are garbled; if you have damaged sensors, your radar goes static-y; when your weapons are damaged you get malfunctions. You've never noticed this?
21: Autodock
If a players (or any other) fighter/bomber is within docking distance (300m?) of a capital ship then the ship is moved automatically to dock with the ship. This assumes that the players craft can be moved "remotely" so to speak... but it's high time we could dock with something other than subspace!
Goober's working on this.
22: Shuddering
When a capital ships main drive comes online (or when it engages its subspace drive) it shudders slightly from the increased energy activity such a device might cause.
The amount of shudder would be miniscule and certainly not noticeable. Do you see a real naval battleship shudder when it starts up its engines? No, of course not. Those inside the ship near the engines would certainly feel something but externally the effect is negligable.
23: Directional Thrusters
I might be getting the wrong impression about how FS ships move about... but in RL rockets and such rotate/change direction via small thrusters. It could be neat to see these little jets firing on fighters / bombers etc as they change direction. Not sure how much of a resource hog it'd be though... This would require model changes that I doubt anyone would bother to take the time to do.
24: Subspace Inhibitors
If a ship is within the field of a subspace inhibitor, it cannot jump out unless it leaves the area (which could take bloomin' ages) or destroys the inhibitor. This could be effected with comm chatter, graphics and so on. Take a page out of Star Wars "Interdictor" class destroyer to see what I mean. Can be done with SEXPs easily... when the ship is in the area, break the player's warp. Make checks on all the ships in the area so they can't leave while this ship is here.
25: Asteroid Storms
Fast moving small rocks are set to move from point A to B (could use the existing waypoint system for this). The storm could be specified with speed, density and area of effect.... could make a change from the average asteroid field. So you'd have a moving 'river' of asteroids instead of the current box? Neat. There would have to be large code changes to simulate the far edges of the river in the distance, however. Some clever backgrounds (the kind that Sesq does) should do this. I can't say navigating through a mobile asteroid belt sounds like fun, though...
26: Improved Asteroid Physics
When an asteroid hits another it should split into smaller chunks and move off in other directions at a faster pace. What's really needed for this is a lot more different asteroid models of a massive variation is size... anything for a little variety. Star Wars: AOTC had a great asteroid chase scene. If we could get that kind of thing in game... well... wow. Asteroids are quite boring at the moment. The asteroid code is already kind of half-hearted, and someone dedicated to improving all aspects of the asteroid code and models would be welcome, but not necessary. This is another one of those long-term projects.
27: Blurring
A blur effect around strong light sources (suns, jump points and so on). Simple but sweet. Eh? You don't find the corona enough?
28: Hull Breach / Weld Effects
Used in ship repairs / construction or where a ship is being borded. Possibly have spark particles where the two ships intersect? Would require the limiting of the electric arc effect, as stated before. Some creativity in impact ANIs and weapon tabling could do this.
29: Automatic Detail Increase On Screenshots
As the name says, this should probably be an option for most people but it'd be nice to have the best possible looking screenshots... hence if there's any way for the game to force the highest possible detail setting in every aspect of the game (and then drop it down to whatever it was before) - that'd be neat. However this could be tricky and also not used much... I'm in two minds myself. You don't always want screenshots to be at their max settings for everything. Let the screenshot taker max out their settings if they want.
30: Ignitable Gasses
Area effect gasses that can be placed either in game or perhaps within containers etc. Hence containers filled with certain cargo are moer / less explosive than others. Exploding containers could reference a certain .tbl tag for explosives with a unique sound, shockwave and so on for each entry (if desired - otherwise a generic effect is used). This would be really neat and emphasise players being careful about what happens to cargo and so on - since a cargo container of meson particles going up would be bad news for everyone in the area - and the effects should reflect that. Expanding the special explosion field of the ships editor could deal with this. Variety in shockwaves is always cool.
31: Nebula Density Affects Flight
Different densities of gas give off different flight charachteristics. So one particular nebula might be dense and provide more resistance against craft going through it - while others may provide no resistance at all. This is a stretch. To actually affect your fighter's performance the consistancy of these fields would have to be as thick as water! Under such conditions propulsion and shipbuilding would have to be completely different, not to mention the plausibility of such a dense field without a significant gravitational source. In other words, it's not physically possible.
32: Collision Siren
Another one that should be an option - not everyone wants this in their ear. When the players craft comes within a certain distance (5m?) of another ship or object, a low collision siren sounds. This is another effort to enhance the feeling of being in a cockpit. Have you ever been in a car with a backup proximity sensor? It can get really annoying. Now imagine that sort of thing on EVERY side of your craft. Best to leave this one out.
33: Subsystem Targetting in Main Display
As the name suggests, the subsystem the player has targetted is surrounded by a targeting box/bracket in the main screen as well as the targetting box. 
The targeted subsystem is already marked with a box (or diamond) on your main screen...
34: Remote Control Craft
Player operable craft from remote such as probes and such... the player can take control of another ship by remote but is still vunerable in their own ship. Can be done with some creative FREDding, I guess. Say the pilot's safely in a remote control cabin on the home ship, like the combat simulator, and that you're controlling a probe.
35: Enterable Nebula
I don't think I need to say much on this - everyone wants it. Could find out the similar kind of system to that that Star Trek: Klingon Academy uses? Still being debated.
36: Supernova Shockwave
A shockwave animation to accompany supernova events.
I don't think this is needed... we're going to see very, very few supernovas to make this a worthwhile addition.
37: Black Holes
Based on a flat plane model/animation with gravitational pull effect on ships. Possibly stretch ships slightly as they become drawn in? Neat effect, but by the time you're close enough to the event horizon you're screwed anyway.
38: Scale Alteration
This one might be considered "BIG". In my opinion the sense of scale in the game is kinda flawed... things like capital ships look big from a way off, but when you get closer to them you can still see an aweful lot of them - the sense of scale just seems wrong somehow. It would be good to redo this to give off a better sense of scale - these ships are supposed to be big dammit!
Done with FOV changes, look it up.
Also, if the ships in the game are re-worked for improved detail and such, missiles and so on should reflect this change and be *incredibly* small compared to the craft that carries them, otherwise it seems that the craft in game are cavernous to be able to carry several hundred Furies or even 6 Helios bombs. There must be room for the pilot in there somewhere! The solution? Reduce the size of ordinance (while maintaining detail).
I disagree; the missile models are the size they are to make them visible and (for bombs) killable. I see no real harm in the current missile sizes.
39: Impact Mortars
Weaponry alteration. Allowance for Fire and Forget bombs with no guidance lock of any kind (but also can't alter course untill they hit something). They're slow moving but incredibly powerful. Detonate around 10 metres away from any large object they come into contact with. With the proximity detonation code ripped from the flak (see number 18) this could be easily done.
40: Momentum
Kinda with reference to the above, objects have momentum so that it takes some time for them to come to a halt. The AI might have to be redone so that ships come to a halt at the end of their waypoints but spend some time slowing down beforehand.
See number 14.
41: Detachable Ordinance
Like the name suggests, missiles and such can be mounted outside the ship that carries them and dropped - exactly in the same style as todays aircraft do. This is especially possible with the upped poly count that HT&L provides. It's fairly aesthetic but who cares. Seems far too complicated and dangerous (for compatibility) with too little gain.
42: Player Controllable Turrets
This may link in with the whole "fly by wire" idea above, but in this players could (REM) link to a turret and control its fire. Again this would leave the players ship dead in the water and very vunerable. You would be better off by cutting all engine power and just rotating in space.
43: Squad Specific Image Maps
If a squadron.tbl references ship image maps other than default then these maps are used instead of the default maps. This could be good to enhance the concept that a SOC squadron of Erinyes might get a custom paint job on their fighters to indicate they were special ops - but the original vanilla paint job of Erinyes could still fly in the same mission without having to worry about changing models around and so on. I really like this idea myself if it's at all possible to do, it allows a lot more immersion without the user having to fiddle around with files and such. Just place all the maps and tables where they should go and you're away. Can be done with FRED2_Open's texture replacement code.
44: Guided Mine Code
When a ship is (x) meters from the mine, the mine fires a one shot rocket at the target - it either hits, is destroyed or misses and detonates in empty space. Have the 'mine' as a zero velocity proximity-detonate secondary weapon that spews one child.
45: Billowing Textures
For effects such as sails, flags and such. Ok there's no air in space but who cares. I'm sure there's a use if it's at all possible.
This
might (and that's a very weak might) be possible in the far future with the HT&L engine using Q3A style geometry shaders, but I know nothing about such things so I really can't say.
And remember kids: search is your friend!
