1) If you are riding in, not flying, a helicopter, and are armed with an RPG, should be able to shoot RPG's from the waist.
2) If no RPG, gattaling gun for control from the side.
3) Hit someone going full speed in a car and that person should be dead. I've been going full speed in a vette and ran somone over, not dead, unless going over jumps and car hits them above the waist. Before you turn around to run them over again or backup over them, they are able to shoot you dead.
4) if riding in helicopter and pilot jumps out, passengers should be able to take control of helicopter, OR...
5) PLEASE Keep the Parachute from Episodes from Liberty city. Can bail out of burning helicopters
Otherwise I find GTA4 to be the best game I have ever played. Was the only game I played for a couple of years and compared everything released to a GTA4 standard. Even now, I can always put in GTA4, go online and have hours of fun.