The licence allows you to install on 3 computers. If you uninstall PBP from a machine you can use the license manager to reclaim/release/recover that instance of the license but in your case, where the machine doesn't start, you need to contact MeLabs. This applies to PBP3, if the version you have is older than that then I don't remember and you should consider upgrading to PBP3.

Any Windows version should work.
If what you have is any PBP3 version then I suppose you're good but I'd consider upgrading to the latest. If you're still on 2.x then consider upgrading.
I have no idea what you mean with Pro/Contro
MicroCodeStudio works fine for me (used to have issues with it crashing not for years now).
Personally I use PICKit3 with the Microchip IPE software for programming. Hardware level debugging with PBP is, unfortunately, useless.