For what it's worth, it looks like your hand position on your spares(at least the washout and 10 pin near the end) is very good for a strike ball release. I noticed the early turn on your strike ball but not on the spare shot, which is what I think you should try to repeat for strikes.
Saw that too. John, what is your mindset on the spare ball? Are you trying to stay behind it, and come straight through, with no turn? Or are you just letting it go, knowing that the plastic ball isn't going to do anything anyway?
I ask,because when I started the relearning process, my very first goal was get the load/unload part down. I decided to keep my hand behind and under the ball, and snap straight through. No turn. Granted, this did not result in much hook, but it kept me from early turning, and showed the rev potential in that technique.
After getting the feel of the snap, you can then incorporate some turn. Some more good advice from this site, from sk8shorty, stating that if you start inside... at say fingers at 7:00...you actually snap the ball pretty much straight up the back.... still getting 10 degrees or so of rotation.
Try unloading/snapping the ball and keeping your palm facing up right through to post up and pinfall. No turn at all. I think this is the key for you... you need to get your arm/wrist/hand to recognize what that position feels like to break the early turn thing. You can add rotation later.
Another tip that helped me was to think about following through towards the pins, and NOT the ceiling. It allows a more natural roll off of your hand, and makes it less likely that you will hit UP on the ball. This applies to the couch drill as well. Snap the ball, and follow through towards the cushions, and NOT the ceiling. Good luck!