My take is that your horse is all the behaviors that you reinforce in some way. Yes, I was all over the place in this post, let me clarify! When you hit a horse for a bad behavior, you validate the behavior for the horse as a way to get attention. Some horses might find any attention, even punishing attention, rewarding. He gets attention, good or bad. A way to deal with this is to reward and praise to the skies good behaviors, even if you think it's silly. He's standing for grooming? Praise? He starts to walk off? Don't say anything just pull the halter and bring him back into position and say good boy, when he's standing again.
Some things obviously you're going to have to have a trainer to deal with. I rode at that barn where the BO would tell the girls riding his hotter than hot show jumper to hit him on the head with a crop when he reared. I don't know if that really worked, but those girls used the crop a lot. Obviously, I was happy that I only rode their well schooled OTTB cause he was an angel.
Thank you for clarifying.
I completely agree that some horses misbehave for attention and that the best thing to do is ignore the bad behavior/quietly correct and NOT make a fuss. However, I don't feel this is at all relevant in this thread, and the main behaviors the OP is concerned about take place under saddle. The horse is not trying to bolt home for attention..
Agree, anything dangerous needs to be dealt with by a professional!