2nd dressage lesson with John - outside rein

Today was another eureka moment - my second with John (the first was when I looked down and realized that yes, indeed, before each fence I *was* pulling back on the reins).  Today's was the significance of outside rein and outside shoulder on a circle.
I haven't seen John in a few weeks, and I had two derbies at Aspen where I could feel the problem, but couldn't tell how to fix it, and I know it has to do with a bigger canter, so I brought my dressage saddle instead of my jump saddle to follow up on the last lesson.
We worked mostly on the circle, and it was still a bit out of my grasp, but I got it much better this time than last time.
First, my questions:
- Do not condition in the sloppy footing.  Work harder and for longer periods inside instead.  So do 6 minutes of canter work without a break, and do harder canter work than I would normally do, like 15 meter circles to a lengthening.  It won't help with the gallop work, but it is better than risking injury.
- To strengthen Charlie's back, more forward/back work is better, and then do short, elevated trot poles, like 3' maximum each, not just the trot/canter elevated poles.
- If I have the wrong lead in show jumping, and I only get half the change, then trot the first few steps of the turn, so I can come out of the turn on the correct lead.  Work at home on the simple changes (simple = canter, trot, canter) so Charlie knows he has to do it within three steps.
- John wants Charlie to be a bit more up and forward for show jumping canter than dressage canter.  So Charlie's dressage canter will have a bit more flexion (head down), but his show jumping canter will give him a bit more lift in his head to look at the fence. 
Ok, so we worked on the sitting trot on a circle, and what John had me do was moving Charlie's shoulders, so that he knows he can do it.  I would lift the inside hand to get him to stop twisting his head left; I would do a half halt ONLY with the outside hand, and I would ride the down transition from canter to trot with my reins a bit higher, instead of dropping them onto his withers.  I would also use my outside leg a little forward (up closer to the girth) and going to the right (clockwise) I would do some haunches in and then bend him to the right.  Bending him to the right was much harder than the left (surprisingly).
If Charlie started to hang on my hands, then I would ask for the half halt with my outside hand, and if he ignored it, then I would counterflex him to the outside.  This would make his inside shoulder pop up, so then I would go back to normal flexion.
When I half halted, it is very important when he gives, to then release the half halt. 
If he gets tight in his jaw, I can also give for a second and then take back.
I could, about half way through, suddenly feel his right rein, which I didn't realize I couldn't feel until I felt it.
I could also - eureka - feel that he would move out through his outside shoulder (if we were going right, he would move out through his left shoulder) instead of bending around me.
The hoppity at the canter is an attempt not to use his inside hind leg (usually going to the left, I think), and I think I give with the inside hand.
I can also, with the canter, open my inside hand, so that he can move his shoulder to the inside.
I still need a lot of work, but with John coaching each movement (i.e. sit deeper, use your inside hip, lift your inside hand, put your outside leg on), I could get Charlie centered and balanced.
What is amazing is how much John knows and how he knows how to tell you what to do when to get a specific result.  And not just that, but how to make it adjust - i.e. the difference between a show jump canter and a dressage canter and why.  And that he could walk me through the steps so that I could make it happen and feel it.  I definitely couldn't do it by myself yet, but now I know that I can do it, and with enough time with John, I'll be able to do it by myself, and even better, know when to use the tool and why.
It was great.  I am really looking forward to working on it.  I feel like just one lesson with John jumps me like a year ahead.  Looking back at the last three years, first - no wonder Charlie is reluctant to change - he's had three years of blowing out through his shoulder and not having to use his hind end.  Why would he think we're suddenly doing it differently?  But second, how much progress I've made as a rider.  Charlie is my golden ticket to figure out how to get a horse round and forward because he's making me learn it and work for it, but while being generous, willing, and responsive. I have to ask, but once I ask, he gives.
I am so, so lucky to have Charlie and be able to work with John.