to the opening poster there they still have the old controls like "hit crouch once and u crouch down. hit it again and u get back up again" there are many ways to "prone" or "crouch" in the game. read through the controls setup and you shall find. i felt sad that it was gone till i spent more time setting the stuff up.
and with the choppers i'm just gonna asume that they wanted to have a more realistic feel for flying cause in RL you would need to balance it on your own without any help of some fancy computer.