I don't think Tremulous would be that good with vehicles. The Q3 engine can handle vehicles, it was done in Jedi Academy, but the output was crap.
On the note of Tremulous in another engine...I was thinking this before. If the DooM 3 engine (Quake 4 engine) ever comes out, we could have Tremulous using it.
OR, wait for a DirectX 10 engine source to come out.
Allow to rebuild armory in SD to stop aliens waiting for SD.
No, no, no, that is what is called tactism and strategie. The reason SD is here is to stop games going on for 60 minutes without a kill. The other reason is it gets the player to use tactics and startegies.