You'll notice in the pics the caliper relocation brackets ,If you have to go back to stock ,just remove those brackets and your set .As for your rotors ,that whole powerslot kit doesnt cost what you said new rotors would be ,you should check those prices again.Powerslot rotors run between $75 and $100 apiece.
As for turning them ,you can ,but realize that even though you may be within min. spec on thickness you will be removing area of slot ,making them less efficient.