If you are so convinced that you are some superb trainer that doesn't need help from anyone, when why are you asking questions about things that I would consider very basic knowledge that comes first when learning how to train a horse?
However, I am confused. You absolutely refuse to send this horse to a trainer, even though he's proven he's willing to buck and you seem to be unable to get him to do something thats relatively simple (crossing water), yet you plan to send your older horse to a trainer because he laid down with you, rolled, and then refused to move on a recent trail ride (which, by the way, is a training problem that even young trainers know how to handle)? Also, I thought this 3 year old was the one that was Amish trained and very well behaved both on the ground and in the saddle?
I suggest you take a closer look at your training abilities. Your 4 year old paint that you called "almost finished" owned you on a trail ride by laying down to roll and then refusing to move under saddle, so you just gave up and walked all the way back to the trailer. This is also the same horse that had the head bobbing problem that you couldn't figure out, but he's also hot/hyper, buddy sour, and travels like a giraffe.
My dear, I think you don't know nearly as much about horses as you think you do, especially when it comes to training one. You are in way over your head and you are too arrogant and naive to see that. I suggest you find a trainer to try to fix your horses and then take some lessons yourself to learn how to be a better rider so you don't undo all the progress the trainer is able to make.
Until then, I will send up a prayer for your horses, they are probably going to need it.