Re: Wall Mounting Rig On Drywall?
I am not sure what your lease agreement terms are but what about ripping the existing sheetrock out and reinforcing the underlying studs or put in wood studs then hang new sheetrock and tape/float/paint it then mount the rig? If you have the capability and a couple of guys to help you can knock this out in half to a full day.
It's better to do it right the first time then wait till it craters while someone is using it and not only having to pay to fix it but also any liability or insurance claim for injuries that may occur.
If none of this is an option then like others have said, use a 2x10 hit 3-4 metal studs and I recommend buttlerfly anchors to help secure the board to the studs. I have found that anything that relies on just threads to hold something to a metal stud doesn't last very long.