[BerntR]

3: I'm too flat with the shoulders going back. Yes.

4: I'm over the top because I'm attempting to not be too flat going forwards.

You're over the Top because your shoulders and hips are aligned that way.

I see a detail that separates you from the great ball strikers at the top. And I think it is important.

You are flat with your forward bend from the hip. And perhaps too flat. So steeper is probably better. But I see something else that I think is even more important.

Your shoulders are steeper at the top than they should be with the given spine angle - on both pictures. At the top, seen down the line, the shoulders should probably be flatter than 90 degree to the overall forward tilt. Take a look at Ben Hogan for instance. Yours are clearly steeper than his (relative to the overall forward bend from the hips).

I believe you are steepening your shoulder turn by bending your spine sideways.

If you stand straight and only do this "spine bending part" of your back swing, this steepening will manifest itself as a side bend in your spine that bends your head and shoulders towards the target. Things may look and feel different at the top, but nevertheless you are setting yourself up to lead the down stroke sequence with your upper body. There will also be a disconnection between this upper part and the rest of your body.

To produce a good, on-plane down stroke you need to produce a side bend in the opposite direction of what you're doing now. One that drops the right shoulder towards right hip, while the hips move forward during transition. The left side of your upper body should become stretched, and the right side compressed. This should happen during transition and kept through the ball. I think you need to eliminate your "reverse" side bend at the top to get there.