I'm not sure if you've made any decisions yet Lorric, but I hope you're still keen to hear alternative opinions. And, having read through this before posting, I've noticed it's coming across as somewhat... dictatorial? Inflexible? I don't know - just consider this a general disclaimer - insert your own IMO's throughout and remember that all this is just my opinion. So, with that out of the way:
There are two issues raised in this thread, so I'll start with the simpler one: your techroom missions idea. Simple answer: don't do it.
Please, don't let my tone there disguise the way in which I mean what I'm saying. It might sound dismissive, and I suppose that's not entirely unfair, but you have to know that using that technique... it's at best inelegant and at worst actively offputting to the vast majority of potential players. As it is, people just don't play single missions in our community. It's a harsh but true fact of life around here. Asking people to play what would effectively be a dozen or so single missions... look, it's just not going to happen. People are either going to be confused or annoyed. Mistakes will happen. People will forget which mission they're supposed to be playing, accidentally click the wrong one - the story will inevitably end up corrupted. And FS2 has a very powerful campaign editor integrated very tightly with the excellent mission making tools which will allow for a proper branching campaign. In this day and age, with Axem's mouse select scripts (Which ar4e actually very, very easy to use) and the various examples already done around the community (Bem Cavalgar, WiH etc.) there's no reason not to allow the player's choices ingame to drive a campaign down a branching path, there really isn't.
To be entirely honest, it feels a little like something I recognize from my own projects - a sort of modding inertia. I suspect tht when you came up with the idea for the branching campaign and the techroom missions, you may have been unaware of the alternative options for how it might otherwise be done? And now that you're aware of them, they feel like they might be too difficult to do right, and besides, you have a perfectly good way to do it already? I've felt that exact way about lots of things in the past - FSO (when it was new), HTL models, skyboxes instead of individual nebulas, using scripts, tonnes of things. It's difficult and a little bit intimidating to learn to use new skills but I promise you, it'll be worth it - especially in this case.
Now, as to the question of whether to use player characters. I'm on record many times as saying that I prefer a silent protagonist in FS campaigns. It's been done well plenty of times (not least in all four of [V]'s official campaigns), and, let's be honest, people don't expect a player character. Adding one adds a lot of headaches to the development, and will inevitably affect people's enjoyment and opinion of the campaign, so why do it? Extra work for no necessary extra gain, and a lot of potential backlash.
My biggest problem with player characters is partly the fact that a significant part of your audience just isn't going to like or identify with the character you create. This is a problem in and of itself, but it's made much worse when the narrative of a campaign forces you to play as a character who makes decisions that you personally strongly disagree with. This is particularly important if you have any kinds of shades of grey in your campaign. As the most well known player character campaigns, the BP comparison is impossible to avoid, so I'll make it here. In AoA, I didn't particularly care about Sam Bei, or identify with the character all that well. Not any reflection of the quality of the campaign, I just didn't click. And TBH, it didn;t really affect my enjoyment of the campaign since Sam never really made any decisions I disagreed with. For all the narrative stuff going on, It was basically a straightforward campaign - the GTVA are good, the Shivans are bad, kill the Shivans. A few things I didn't really understand were going on, but whatever, no big deal. However, this got turned on its head in WiH, where things were much more complex, and as such, being railroaded by the character of Laporte and the narrative necessities of the storyline was much more jarring.
So, given all that, the logical assumption would be that I would be advise against a player character. Well, almost. The reality is that all of the [V] campaigns and most of the user made silent-protagonist campaigns have been relatively black and white affairs. Very rarely have the kinds of shades of grey that WiH was able to play with been prominent, and in all honest it might be hard to play with those kind of narrative ideas with the player remaining utterly silent all the way through. However, you have an advantage that they didn't have in WiH in that you are specifically setting out to make a branching campaign. Eliminate the rails, and suddenly railroading ceases to be a problem, at least in theory.
So my suggestions would be thus: If you want to make a basic, traditional, Freespace sort of story, where the morality is pretty straightforward, keep your player silent. It's easier and will lighten your load, almost certainly making the campaign better. If, however, you want to tell a more morally complex story, then a player character might be inevitable, but for god's sake branch your campaign whenever the player has to make a significant choice, and let the player, not the writers, decide how that character thinks and works. In my opinion, those are the two peaks in the continuum of options available to you. Deviate from them, and you'll struggle.
