Nutshell - now that it's up to date

I bought Mercury as an underweight pasture horse who hadn't been ridden in a year and had been ridden for two years by a teenage girl before that. He has a tattoo, and was called an "Appendix QH" when I got him. The woman who sold him to me was a year off about his age. He is 12 this year (2006). We can't read the letter on his tattoo, but we have a good guess which horse he is with Jockey Club because of the numbers, gelding, and color. I haven't paid for his history to find out how he did or how much he raced.
I had him at Griffinwood for several months, and he was happy there, but it was too crowded, so I moved him to Bob's barn, Edelweiss in the winter. I'm much happier because the arenas are huge and I am usually there alone, and there is a cross country course. Griffinwood had trails, and right now I am truckless so he isn't doing any trail riding.
He gained a lot of weight and we got his feet fixed up so he could move better. He's working on balance now, and has started to trust me and move better (Bob says because my balance is better too). Bob has completely changed my riding style from hunter/jumper to a nice, solid deep seat. I feel a lot more secure and comfortable, and can even sit a slow trot! (A miracle!) I consistently have problems keeping my hands still, and we are still working on Mercury's health. He is getting Missing Link and an herb blend right now (from Chamisa Ridge, called "Rest Easy" for nervous horses), and biotin, because his hooves got weak a couple months ago, and when the farrier was a week late, he finally pulled a shoe. We think his hooves were weak from the "starvation" period - when he arrived skinny, his hooves were malnourished that year, and finally grew to the point that the nails were in the thin part. Now I moisturize twice a week.
He went to his first show, a derby, last weekend. We rode "Beginner Novice Intro" because I had no idea how he'd act at a show. I thought he'd be nervous and strung out and not listen. I took him a half day early and rode him around about an hour and a half on Friday, and he was really nervous - ears looking, jumping around, prancing. Saturday and Sunday we had a dressage test, about an hour break, and then a combined stadium/xc course. He did excellent! He got a 3rd place on Saturday (Dressage test was a 40) and a 1st place on Sunday (dressage test was a 39.5). Debbie's husband videoed the show and made me a tape.
Today's lesson was the first post to this blog. I missed a few lessons and there was a period of about a month where Bob rode because we were having problems with him. He might have an injury to his sacroiliac. His hocks wobble (it feels like he's about to sit down - he stumbles when I'm riding sometimes); and he tends to get stiff and have trouble pushing off from the hind legs. When I work him on the bit, he gets lame. We've had the chiropractor out twice, and we're planning a third visit. She got rid of the bulge, and he does better for about a month, but with work starts to get stiff again.
I hope he can go up to novice, because I'd like to keep him a few more years, but I'm not sure how his back and hind legs will do. I'm working on strengthening him right now. He loves to jump, and is doing really well. He goes through water without any hesitation, and he doesn't always know where to take off (and I don't always tell him the right spot), but he tries and doesn't do anything bad (no rushing, running out, hesitating).
Bob said in today's lesson that one thing I do is get lazy - once he is going well, I quit asking, so that's a problem jumping (I expect him to do all the work) and in the canter, when we plummet to the trot, usually I've quit pushing with my leg.
Mercury is kind of lazy, and I'm used to riding horses with more spunk. He's a funny mix though, of being lazy yet nervous. We don't want to start using spurs because of the nervous side.
I need to do one more post - the last lesson Bob told me to write out in detail what my hands are doing in the trot, to help me visualize all the details to work on holding them more steady. Today's lesson he gave me a lot more details, and the problem I've had is keeping it all in my head at once. It turns out I can only do about 15 things, then I start losing them, so I've been slowly working from the macro to the micro.
Bob has improved my riding enormously. I haven't even been riding with him a year and I feel like I'm at least 100x better than when I started. He is really, really good at explaining what's going on and why, so I can feel it to fix it when he's not there.
It's been very frustrating that I can't feel all of it by myself.