Rising up on the backswing has been a long time problem for me. If I feel like I am... bowing down I guess or getting back into the hip joint then I am good on that. I am making the angle between my upper trail leg and my back more acute. Maybe those things would be useful for you when you are doing full mental involvement swings?
As for maintaining spine angle through the ball I 'feel' like I am doing pretty well on that... LOL when shoot some video I am pretty certain that I will find out otherwise. I think that I am starting to feel the positions though. I find that my accuracy is better when I finish still leaned over towards the ball as much as I can. So I guess that helps me maintain the spine angle a little better through the ball. The problem is to keep the weight back where it belongs and my lower back arched and upper back straighter. I do find that posing in impact position and then making small IMA impact backwards drill swings seems to help a great deal. It allows me to feel the 'correct' impact position while moving and then it seems that I am getting back closer to that when making full swings.