Greg, thank you for your feedback. I've been waiting to reply so that I could think about your response, particularly in the snatch feedback section:
Once you're past the knees, though, you throw your head back, which will encourage you to reach the hips to the bar rather than pushing the bar back to your hips. The latter will help you extend completely while remaining properly balanced, whereas the former will have you moving into the bar, which means less speed, worse timing and bad balance.
Related to the hip problem - you need to punch down w the legs as you snap the hips open. It's like trying to accelerate off a soft base. Punch the legs up and then pick the feet up to reconnect them flat with the ground right under the bar. You're puling too long - punch the legs and snap the hips, then immediately pick up the feet and pull down like described for the tall snatch above.
I think I get the head back concept and it is something I've been really working on to the point that i've made a target in my garage gym that I try to keep my eyes on at all times. I think that I just don't understand how to open up correctly in the 2nd pull. And, because I can't think through it conceptually, I can't practice it. I don't totally get what you mean by punching down with the legs and snapping the hips open like accelerating off a soft base--at least to the extent that it is different from what I am already doing. When I really break my video down, I can sort of see myself moving forward in the 2nd pull as the bar approaches my hips (and again on the pull under... but I'll try to fix that another time). And again with "punch the legs up and pick the feet up"... How do you open up from the first pull with vertical hips and without losing tension all the tension you've just built? I can't even conceptualize it.
I'm frustrated, but I totally appreciate your feedback. Hope all is well.