"PULL (AKA the Problem)- While I'm a Joel Turner fanboy, I don't do well with psychotriggers, so this step messes with me. Some days I slip into this weird daze where I am gently expanding and the shot flies great. I also know from experience my shot collapses if I don't have some focus on my back tension in this step. But a lot of the time I either get hung up on pulling, and my fingers get really grippy on the string, or I overpower this piece, and throw my whole body alignment off by the violence of the release."
You kind of name your own solution here; "Some days I slip into this weird daze where I am gently expanding and the shot flies great." This is your key. BUT, it takes some concentration to make it happen like this.
Many shooters allow their thoughts to start looking like a kid's sparkler on the 4th of July. Bright sparks (thoughts) flying in every direction. The harder you try to think about this, the brighter the sparks and the less direction.
Try an approach like this. Get your first 2 steps done, at this point I'd add that if your REALLY have bone on bone, and are maintaining it, you CANNOT collapse. So get your bone on bone, set your aim (by WHATEVER method you use) then ALL your thought concentration is on your back and maintaining your bone on bone. Now everyone thinks differently so try and then choose one of these thoughts to conclude the shot.
1. Think "close the car door" using your string arm elbow.
2. For me, I like the thought, " lean on the wall harder with the back of the string shoulder." As I draw, it feels like I am leaning on a wall on the string shoulder blade. The feel of that "lean" gets more intense as I come to full draw (that's loading the back). Then when ready to shoot, I lean on the wall harder and the shot happens.
3. I personally don't care for this one too much but it works form some folks. That is to move to a "third anchor." That would be your follow through position.
In all 3 of the above suggestions, DO NOT think about what your string hand is doing -- it is a non player. IF your thoughts go to the hand or anywhere else, you are thinking about the wrong thing. This is so easy to do (think about the wrong thing) and so disruptive to a good shot.
In your description, it sounds like you have found it on occasion but that is what you need to try to repeat. These are blank bale and blind bale exercises to really learn how to direct your thoughts to the place that works best FOR YOU.
I see this often with folks I coach and it is a tough one. Controlling your thoughts is the toughest part of archery. Those that learn to do it are the top shooters we all admire. Those that don't or can't are the rest of us.
Arne