Great write-up, thanks! I see it's been a while but I'm curious if you ever did the center caps too or what was the outcome of stripping it? I'm looking to refinish my wheels and to me it makes sense to do the caps at the same time so that the finish matches. The biggest concern here being that the bowtie would probably be stripped/sanded away.
I've not done the center caps yet. I've tried stripping one, but it's kind of a mess right now. The wheels came out perfect though. If I don't have luck with the center caps I may buy new ones from GM.
Painting Aluminum is trickier than you might think. There's a special process you have to go through and special chemicals to use. It can be done; I painted my boat's outdrive successfully. But if you don't follow the proper procedure for painting aluminum, the paint is just going to chip and peel. Unless your wheels are screwed up though, a polished Aluminum wheel is going to look far better than any paint job, IMHO.