I'd like to suggest some stuff...
*The possibility of adding music onto the title screen (For mods and stuff)
*An in-game music player
*The ability to change the names of weapons, teams, (Terrorists, Counter Terrorists) NPCs, etc. (For modding purposes)
*Dynamic lights (And the ability to disable them in case they lag)
Dynamic lights example:
*More realistic deaths (Instead of someone disappearing when they get killed, their corpse lays on the ground)