??? can't you just partition your hard drive and install more than 1 linux?
try a live usb first?

I might try, but it is not "just". I don't want to risk losing my personal AND work computer for however long it might take me to try to do it. I'll return if I get thus far and still have problems mounting :)

but you still have the live usb option.
with that you can still access user data on your hard drive.

you can even install and run a system on a usb (not to be confused with creating a bootable live media).