The rearing is not your concern. This thread is not about rearing, it's about slowing down.
Let me just make this perfectly clear to you. I DO NOT have a bad horse and he is NOT a PROBLEM!!! He's YOUNG and needs TRAINING! He got almost none at the ranch he was at before I bought him. They told the people to kick to go and pull back until he stops. I trained him to rear on command, and guess what!? He rears ON COMMAND! All you did, was read what I wrote which was only about a problem I had, then looked at my picture and judged. You don't know anything about his personality, how smart he is, how willing, how forgiving and now you're calling him a bad horse and a problem. That's like saying, "Oh, your horse weaves, that's a problem, it's a bad horse."
Now that that's over . . . thanks everyone for the advice, I'm going to see him right now and we'll see how it works out.