Oh also forgot to add work on making him lighter on the ground to your cues... a touch of the whip to his hip and he moves off no matter where you are... round pen, arena, pathway, trail. Take hand walks and work on sensitizing him to you and your cues. Start teaching him to bend and move laterally on the ground and get him light and sensitive. Remember the more you kick with spurs and whips on horses like this sometimes you can make them less sensitive. You want to move progressively up in pressure. The lightest tap you can manage then a touch more, etc.. until you get the reaction, then praise, rest and repeat, until you get as light and responsive as you can.
Practice that on the ground before you get in the saddle, and you will have a much more sensitive horse. I have one that was dead in the sides for leg pressure. Spurs sent her shooting to the other side of the room so they were not an option and I had to find a new way to approach things. Now a light touch of the leg and we are off. But we started on the ground, this including getting our lateral movements on as light a cue as we could muster. Now if I look at the hindquarters with the right body movement they move the direction I want. This translated well to saddle and she became wonderfully sensitive.
This approach of light to (and MANY increments in between) harsh to rest, rinse and repeat has worked on every horse I have put it to. Including a 19 yr old barn sour, ranch gelding that hadn't been touched in a year and had a habit of kicking (aiming well, I might add ducking was handy) at anybody who asked him to move out in the round pen, at the end of three months and only working a couple of times a week we were riding trails and solidly working in the arena light and sensitive and staying in gait. To be honest I trusted him enough to ride with my eyes closed and work on balance at trot/canter, and did not hesitate for anyone to ride him.

Mmmm... Apples!

<a href="http://dragcave.net/viewdragon/AxGg"><img src="http://dragcave.net/image/AxGg.gif" style="border-width: 0" alt="Adopt one today!"/></a>