As long as there is air friction complete zero-g is highly unlikely. It takes a lot of training to set the engines correctly to cause zero g by compensating exactly the air friction
A malicious pilot could injure/incapacitate anybody who wasn't strapped into a seat with aggressive maneuvering. I expect it takes a lot of training for a 'vomit comet' pilot to not toss everybody around like ragdolls, but a suicidal pilot trying to kill everybody wouldn't be gentle about it..