Typically, in my experience, official Linux support isn’t required for a good experience. While the last thinkpad I used with a tablet was an x41 I guess about 15 years ago, I’ve been using thinkpads with Linux continuously since before then. It’s amazing to see manufactures officially supporting Linux now, but once the hardware works in the linux kernel, it tends to keep working on all future releases. It’s not like Windows where you need to go to the manufacture’s website and download drivers, they are open source and are kept working by volunteers for a long time.

Please do your own research, but in a quick search it seemed like the Thinkpad X12 was working well for some people with modern Linux distributions. I know some people use Linux on the Surface Pro’s and I almost bought one once, but decided to go with a wacom tabletop monitor/tablet instead.

You can. I recommend making sure you have logging in place so you know what’s going on. This could include not just service logs but firewall logs as well. You might want to rate limit the connection attempts for SSH and WireGuard and consider Fail2Ban or something similar.