In the spirit of sharing...

[TOGWT]

1. TOGWT do you have any idea or reference as to how much of a paints thickness is removed by regular polishing with various different combo's ? For example Menz Power Gloss on a wool pad, or SIP on an Orange LC pad ?

There would be so many variables, 'hard' or 'soft' paint age of paint, mfg, etc, etc

2. Many compounds are listed as being able to remove 1500grit sanding marks so I would assume they remove as much clear as what wetsanding with a similar grit would, or am I mistaken ?

You are not mistaken, that's why 'grit number' was chosen as the "benchmark" for scratches and scratch removal