they got a bunch of stuff at your local auto parts store to clean that up, comes off pretty good too.

I got that on my oxidation too. This is caused when you park in the sun and it gets hot enough to fry an egg on and somebody does. If you use Pam eggs don't stick.

It's the clear coat disintegrating. Get some white polishing compound from an auto parts store (white, not red) and polish it with a buffer. You may need to polish it several times before it works. Finish by waxing, and the polish will remove all wax from the paint.

It's already off, that's the problem. You'll need to get the bumper repainted.