Dedicated Rush maps.
No vehicle game mode (Soldiers only).
Get rid of levelution rubbish unless it's implemented properly and not just an annoying once off in game effect (Think a massive snow storm that blocks off paths, while creating new paths, disabling Jets/Choppers ect).
Make sniping more realistic (Players will need to take wind direction and wind speed into consideration when firing over long distances)
Give us a larger selection of vehicles to choose from.
Make anti air/anti tank crews a thing (Think a crew of 2 or 3 players that can deploy a stationary flak cannon, that can be assembled and taken apart and moved around) .
Same with vehicles (Think Jeep that can have a rocket pod attached to it while stationary, rocket pod will have to be removed before driving or it makes the vehicle super unstable/slow).
Just some ideas....