#1. LOW GRAVITY option on all maps past,present & future & all Modes, randomly activated by server and/or squad vote before match begins to activate WoooHoo !! [Very important,unlimited Ceilings in maps to accommodate!]
#2 Allow discharged weapon projectiles rounds to continue on its trajectory and target even after firing bot has being destroyed (excluding some energy weapons, since some travel at spped of light).
#3 Invasion Mode OH YEAH! A combined Green team from both sides working together protecting a Main Base or Red verses Blue teams. To see whom can repel and destroy the most attacking Alien waves, each wave a bit more intimidating until all waves have been eliminated.

Love the implementation of Unreal Tournament features, one was using the ALT firing mode on all weapons right click or left click, on the fly depending on moment to moment engagement.