The only change needed for RP servers would be a chat bubble sign, (thing pops above your head, showing your chatting.) And more lines for the chat area.
more suggestions I have:
8: FEMALE models. I've pretty much seen all male models on tremulous, (except for aliens who have an undeterminable gender) and I think there needs to be an option for female models, so this game can appeal to girls who play. (Even though i'm a guy, I still think there should be that option to make it appeal more to other people.)
9: Customizable bodies/faces - I think you all are familiar with this, the ability to change your look in games could highly increase popularity, since it's somewhat boring looking at an army clones.
10: Customizable items - the ability to paint/color your armor or anything your holding/wearing to a different color/shape.
11: More buildables - possibly small vehicles/weapons or the ability to build walls and gates. Maybe even watch towers and such.
12: More weapons (I suggested this earlier, but wasn't specific on what.)
Aliens:
A: Spider string - able to pull humans to you (only able to use a certain amount of times on one type of alien?)
B: Sonic Roar - temporarily stun a human by making a loud roar.
C: Acid - (similar to the human flamethrower, except the aliens spit acid)
D : Suicidal explode - The ability to run up to a human and blow yourself up, which would cause your acidic blood to hurt and poison the human. (does not affect buildings however.)
Humans:
A: Single/Dual magnums (Halo 2 style, new alternate for blaster/pistol)
B: Laser guided Sniper (A sniper rifle with a laser on it and scope)
C: Swarmer (fires 5 plasma bolts at once in a spread shot)
D : Advanced Blaster (Also an alternate for the blaster, fires stronger shots)
E: Mass-driver pistol (Self explainatory, fires a single strong shot, but is an alternate for the blaster/pistol, and is weaker than the mass-driver)
(I would have more ideas, but my mind is kinda blank atm. lol)
14: Trade ability: Able to trade not only credits, but items/weapons as well.