A few suggestions regarding RPG:
I have noticed the travel speed of the RPG/AT round is somewhat slow, in reality (I know, I know.. this is not a simulator) they travel fairly fast, almost 300 yards a sec. this would give the RPG a better chance vs the helis and vehicles (which now dodge rockets very easily and are hard to hit with the crappy iron sights the RPG systems have).
I believe this would be a great change for the use of the RPG as long as a back blast system is implemented.
A back blast system that kills/injures the user if used with an obstacle behind or that kills a teammate if he's within 10 feet behind of the user to prevent the weapon from being used in CQB and/or recklessly. This would define the RPGs place in the game mainly as a primarily anti vehicle option, while leaving room for under-barrel grenade launchers to be used more in CQB and anti personnel roles.
Another option is to give the RPG different warhead choices, including thermobaric for anti personnel use or HE for lobbing a rocket into a room from far away.