RE: Low flyover
Read somewhere that a guy called Richard Bong flew his P38 at lamp post height in a small city street while training .. the local authorities wanted to put him in jail. Obviously his career wasn´t finished as he turned out to be the greatest WWII American ace.
Hard to judge things like this. IMO as long the guy is not flying near the envelope ends of the aircraft, it is OK to do a not too low pass.