I went over my shoulder-in and turn on the haunches video with EP and some key points came up:
*horse is sluggish/not forward enough for this level(1st/2nd)
*shoulder-in's are ok but need more power and collection(see above)
*turn on haunches are not correct-too wide-not a collected enough walk to successfully get the exercise(see above-no collection without FORWARD)
*rider is using gluteus muscles too tucked, in all work, which blocks the flow of energy
*rider needs to narrow her upper body during the half halts to help draw the horse's back up
I think I would be much more discouraged if I hadn't thought many of the same things watching the video and by happenstance the next day had a great article pop up in my Facebook feed about the correct half halt. In Dressage Today, and by Conrad Schumacher, it gives chapter and verse but somehow succinctly, and I realized (duh!) I had no drive in my half halt sequence. Basically CS defines the half halt as drive-bring back-drive with minor variations for gait, transitions, and etc..
So, after I posted the video I had a lesson lag of about a week. I went out and added the drive on either end of the half halt and OMG I have a much more engaged, fluid horse. Because my bio-mechanics are better than they've ever been, the half halts come through, and we have engagement, with some of the best transitions, lengthens, and stretch circles we've ever gotten. Now I will add in the smaller bio-mechanical corrections, keep working on the shoulder-in and haunches-in on short tracks and come back to the turn on the haunches after we get the engagement better for a couple of weeks.
Feel like this is a HUGE breakthrough, and will post comparison video soon.