You tried different screws, but try screwing it with no binding at all? Most bindings barely let you start threading the hardware in because of the tight tolerances given the baseplate/disc thickness and the necessity to prevent bottoming out the hardware. If you aren't cranking down on the binding, it most likely won't mount. Try it with only the hardware. If it's galled, just take an M6 finishing tap (make sure it's not a drilling tap) and rethread them. If it's stripped, you could try a HeliCoil but I'd just warranty the board.
As for the scratches, treat them as a badge.