lol.

Polish no questions asked, it's completely pointless to chrome aluminum.
Anything can be chromed/electroplated, look at most of the plastic grills on cars & trucks in the last 10-20 years or even hub caps...it's plastic that's been etched for texture, coated with nickel, then the chrome is applied. Had a guy in Oregon offer to do all the plastic on my Triumph Daytona years ago for free BUT shipping all the parts to him and back was gonna cost more than I wanted to spend then i would have to figure out how to get the tank to match other than painting it black.
As for the BBS wheel, you can have it media blasted to clean it up...just like sand blasting but they use a differant medium: could be anything from glass beads to crushed up walnut shells depending on the condition and the look desired.