I'm wondering, would you accept testing on a VM? I don't know if you've got any Linux testers yet, but I can give it a try on a Linux VM - if possible. There shouldn't be much difference, if it runs on a VM it should run natively.
I've sent you the email with the Steam key! the instruction is in there and it'll greatly help me if you can give me answers in a day or two at most. In other words, I need them ASAP :'D