I have the yellow, orange, and white pads as well as the Menzerna products you mentioned. I also have 1 red pad for applying glaze and nothing else. The yellow pads don't see much, if any, action - and all they see are my compounds (e.g. HTEC, IP, 3M PI-II)
If you have noticeable swirls then start with the orange pad and the IP. I know the convention is to use least aggreeeive product first, but I haven't had much luck cutting swirls, etc. with a white pad. BUT, I know my paint and what will work so you might want to experiment and find what pads/products work best for your paint.
If you have pretty minor imperfections then start with the white pad and finish polish and see where that takes you. I would advise against using a compound (such as IP) on the white pad if you are going to use that same white pad for finishing. You don't want to mix a compound and a polish on the same pad because some of the compounding reside will remain when you are trying to do your final polish which will work against you somewhat. If you do use a white pad and a compound, then just wash it out good befre using that same pad to finish with.
I would also not use a gray pad with the final polish with a PC. I've heard people have had good results finishing with a gray pad on a rotary, though.
Just out of curiosity, what pad would you apply the wax with?
So, to recap, in general:
orange pad - IP
white pad - FP
gray pad - wax (although I prefer applying wax by hand, not machine)
These are just my opinions.