If he was an ex-rope horse, he will be a little hot blooded and especially in the arena. It sounds like you are doing good with him and yes it does take A LOT of patience :) I would work on a really good head down queue and make sure he has it down fantastically at a stand, then at a trot and so on. I have found that when a horse gets excited, usually the head will come up which means there is less blood going to the brain and more excitement. So by teaching him this head down queue, you can bring his headset down and keep him calmer. It can be a good amount of work but it sounds like you already knew that, you said he has come a long way. Be positive, don't get discouraged. :) Hope this helps a little.