Titan, you sound like you are proposing a complex, story driven single player game. Not going to happen. The work required for even a single SP level is huge, plus it would need a wide variety of character and scenery models, plus AI, plus the writing and event scripting.
The project needs to get to a useable state as quickly as possible, and then evolve from one usable state to a better usable state in jumps as small and simple as possible. This keeps interest alive, and maximises the chance that at least something useful would be left when the project dies a premature death. Remember that the failure rate on mods is huge. Most never really start. Of those that do, 90% or more die before they're complete. It could conceivably move up to a full single player game, but this is exceptionally unlikely even if it gets off the ground at all.
Suggested plan:
- Start with Vasudan and Terran Marine player models for an existing FPS, as suggested by Galemp.
- We need to make decisions about the behaviour of weapons and the movement of players. Do we want Quake World or Day of Defeat? We can refine later.
- Then we commit to an engine. Player models need to be rigged and animated for this engine. Other models, including weapons, can be represented by place holders. A single test map. A simple classless FFA game mode. If we can't get running around killing things to be fun, the game will suck.
- Shivans! Animating these is going to be fun. Mapping.
- Team FFA. Shivans need to be outnumbered. Mapping.
- Proper weapon models. Mapping.
- Then implement a class system. Also, mapping.
- Then more interesting game modes. Alien versus Predator 2 had some fun modes that had one side as the aggressor, and the other fighting for their lives, precisely the atmosphere we would want. Maps need to support these modes.
- Objective based game play (e.g. the Enemy Territory games, Jedi Knight: Jedi Academy siege mode) would be excellent, but would be harder to achieve than any other MP game type. It would require more code for the game type plus more mapping and more event scripting for each map compared to other modes.
- If we get this far, with a good selection of highly polished objective maps, then we can think about SP.
Some of these can be done concurrently, with mappers, modellers and coders working on different bits.
We just need committed and competent mappers, modellers, animators and coders. FSO does not teach people to map, and the animation it may need is very simple.
I can code, and I have experience modding the Quake 3 engined JK:JA (unreleased mod

). Whether I would wish to commit to this project is a different matter, "real life" and all that. Certainly there would need to be a team that looked capable.
No offense or anything...
but Sauerbraten is fugly
Is that fugliness inherent to the engine, or a product of the artwork? The models are almost all very crude, and the textures are often not very good.