@livetoski, boy I've never met a skier who skis so much, looks so much and has as many as the same problems as I do. Carbon copy I'd say kev, so here goes.
You have described the same situation as I have that when the ski DOESN'T bite, it's a smoother turn but, you lose angle and go downcourse. When the ski does bite, (over rotate) we are not in a good athletic position to absorb it therefore we bend the waist, absorb it with our upper body, handle blasts out the front door and ski goes flat and downcourse. Barf!
Take a look the the pictures in the link I posted a while agohttp://www.ballofspray.com/forum#/discussion/comment/55050
My point was that in the preturn, my weight is too far back vs better skiers. This comes from too much speed too late. In the turn then having to 'dunk' the turn, over rotate and bite off more than my body can chew. Sound familiar?
First observation is that your pull is from your arms, very high and not connected to your hips. I think someone said sliiide your hips to the handle, while keeping your shoulders higher, less closed. What I do to achieve this is drive my knees and ankles while more bent, forward on the ski, that gets my. Shoulders further back and my body more aligned to take the pull of the boat.
The 2nd thing is that you are not counter rotating enough. (I have to think about this. At every ball!) a little bit of more open shoulders will allow your hips to clear better and you can stand tall on the preturn and gradually, more predictive get more of the ski in the water earlier to prevent the unexpected 'bite' from over rotation.
Last thing is your free hand needs to stay quieter, by your side, not sweeping forwards and backwards, mine used to go up in the air. Finally got it to settle down by my side keeping my COG better and ready to RECIEVE the handle when your hips sliiiide into place.
Sorry for the book on your skiing but it's soooo close to mine I have lots of notes and coaching to offer. Keep it going though, because when form all comes together for 6 balls straight, man, what a feeling!
Here's to getting more of those feelings, more often!