You should be able to turn a turret on or off. Mostly for the rocket turret so you dont splash damage your own team if you dont want to when it autofires.
The ability to save and rewatch games
The ability to go into a game when its the other players turn and look at the layout
A future position line of sight prediction. This would allow you to select one of the weapons from a list, select a spot on the map, and it show the range / damage for each sqare in the range. At a minimum you should be able to see what squares you can hit from your current position. The only way to do that right now is if someone is actually in the spot you want to fire at then obviously you know if you can hit them or not. I want to know what squares are LOS blocked even if there is nothing to fire at at that moment.