I havn't read all the posts, but are you handfeeding your horses? I found that certain feeds would make my horse go completly nuts. I also discovered (after many throws!) that my pony didn't like being ridden in his paddock. We were of the opinion that he had been abused by previous owners, nightmare being ridden in his paddocks, dream come true out of it. It is hard work and frustrating, I was lucky that he ended out to be a cool dude! Good luck