This might be really bad advice, but at my camp when a horse would start pawing I would pick up a piece of gravel and throw it at the ground underneath the horse. Don't actually hit the horse, just the ground underneath.
It seemed to work excellently. The horse doesn't think anybody's throwing the rock, they just figure that every time they paw they get this weird thing happening under them. This method probably wouldn't work so well in a stall, but it'll work in an arena.
Another idea about pawing: Maybe he needs more turn out time? Is he gelded?
One of the horses (a gelding, gelded late I think) at my camp would paw continuously when he was nervous or if a mare was in heat. Basically with him I just tried to make sure to give him lots of attention since I was his love and I tried to give him things to entertain his mind, like letting him graze loose outside the pasture, etc..
I'm not sure what to do about those other things.