You never log in as root. On every new VM/LXC I create, I delete the root password after setting it up so that my regular user can use sudo.
Run as your regular user and sudo the commands that need privileges.
Also if these are servers, run them headless. There’s no need for a GUI or a browser (use wget or curl for downloads, use your local browser for browsing)
If you check out the Steam Community for it, there are tutorials to getting it working.
I’ve struggled with controller support and the “camera drifts into oblivion forever” bug, and eventually ran out of time to mess with it. Would love to get it working again someday.
If I may interject here, but in actuality the system users are using is not, in fact, “Linux” but is actually GNU/Linux, or as I’ve recently taken to calling it, GNU plus Linux
Other posters are right in that KVM is the same on just about every distro. Proxmox comes with extra tools for management and I think that makes it especially well suited.