Overturn rims yourself?

Hello, I have got a few heavily used alus to my finally bought audi 80 b4. they look very damaged and I have the incredible advantage that I have the experience and the machines available to overturn them. my questions are now the following: 1. a plastic-like layer crumbles off at the damaged places, is that the clear varnish? 2. can I get the valves somehow out of the rims? 3. if I have partially turned off the rim, I have to then shine down the entire paint, or can you just spray over it with clear paint? here are some more pictures of the heated dinger….