Yoda - I agree with everything you say in post #27.
I personally like your idea of keeping the head centralised between the stance at address, and then shifting the pelvis slightly leftwards to get slight right spinal tilt. However, I have noticed that many PGA tour players prefer to have their head slightly behind the center of their stance at address.
I agree that they generally all have very stationary heads, except for slight head swivelling.
Thanks for these sequences. We all do better when we can actually see these principles in action, and your skills in this area are a wonderful contribution to the educational mission of our site.
A question regarding your sequence of Stuart Appleby:
In Photos #1 and #3, my guess is that the yellow line represents the spine and its inclined angle to the ground ("axis tilt"). But what does the line in Photo #2 represent . . . the original angle per Photo #1? Thanks.