We've come a long way since burning 'witches' at the stake. /s

As far as I know, all Rimworld mods will work with Linux. You can either subscribe to them on the Steam Workshop (and enable them from the mod menu in-game) or download them manually and put them in the mods folder in the installation directory. I've played with modlists that had more than 100 mods in them and never had a Linux related issue.

To answer your other question, I dual booted Linux for a while, mainly because of privacy concerns, but switched to Linux full time around the time Windows 10 came out. The thing that gave me the final push was Windows 10 on my new laptop telling me it couldn't open a zipped folder and I would need to pay for that feature! There was also a backup copy of W10 on a second drive that I didn't know about which automatically overwrote Linux when I tried to install it.

You could try using Lutris or Bottles and see if either of them help. As a last resort, just running it through Wine after fiddling with the settings might work, but it's a long shot.

EDIT: found this page that talks about a DLL that's needed to make it work on Windows 10. Assuming it's the game you're talking about, that might help make it work.

This gives me more existential dread than it reasonably should...

Not been using them for long, but so-far Hetzner seems quite good. Just a heads-up, though: you will probably need to provide them with a copy of government issued photo ID (e.g. passport).

I wildly underestimated how long it would take to scroll through that! 😱