Is it very risky to install TCs?

[Khyrpa]

It seems very risky to take a full conversion, put it in the MAIN FOLDER, DELETE ORIGINAL folders, risking the game to stop working. Should I take the risk to install one, but create back-up folders first?

Delete original folders? No full conversion should do that. Only thing they should do is create new folders for their stuff, or put that stuff inside the original folders. No actual file should be overwritten.

And at least I don't know of any full conversions that deletes stuff...