Nice job fixing that paint! Thanks for the overview of the OP/OC. I have got some OC and OP that I have yet to use. I would have normally cleaned off the residue after each product but I guess that is not necessarily required if you know what the result is going to be.
I would go with 5.5" CCS pads on the PC/UDM. If I had a Flex, I would probably try 6.5" pads due to it's power. 4" pads might come in handy for the tighter/smaller areas. I have had good luck with Menzerna polishes but also have some Optimum that I need to try.
The only thing giving me a dirty look is my credit card and it's $300+ bill:p. But I know I got the good stuff and it will last me a while. All 21 Lbs of it. :buffing:
I didn't take pics of all my products yet but...