Does window tinting protect from UV rays?

Yes it does, and the stronger the tinting, the more it protects from the sun and from the heat it generates.

Can you remove tinting without ruining your windows?

Yes, car tinting can be removed without doing any kind of damage to your windows as long as the person doing it knows how to get the process done properly.

Can you do car window tinting yourself?

Yes you can, but this is the kind of DYI project that often ends up with bad results and this means you would waste your time and money.