Start with a portable hard drive which only has one job “store a copy of your critical data”.

• move the drive as infrequently as possible, especially when it’s turned on.
• only ever write to it when you do your periodic backup.
• only plug it in when you need to read from or write to it.

It’s a paranoid set of rules, but if this data is critical, this is a good idea. Even better is to have an additional copy of that data in cloud storage.

As far as operating system, you absolutely can use a Linux machine, but learning a new system risks you accidentally deleting data so be careful. Linux has ways of reading windows-formatted hard drives, so as much as I prefer Linux, I would say don’t try new things on the machine which hold critical data.

What are your route & dns settings? I don’t remember if tailscale forces all DNS queries to go via it’s tunnel, but I remember that the mullvad client uses DNS hijacking to make sure the device uses the wireguard tunnel.

Is this on a fresh install, or have you installed a Wayland DE on an existing distro? If so, you may be missing some packages. What DE are you using for both X and Wayland?

I’m surprised wlr-randr is missing a display that xrandr can see, they should be looking at the same place for the display info. If you hunt through dmesg do you see any errors related to “EDID”?