You would leave your plex config and db files on the disk and then map them into the docker container via the volume parameter (-v parameter if you are running command line and not docker-compose). Same goes for any other docker container where you want to persist data on the drive.

I was able to install docker on mine. I don’t remember if I had to grab the installer separately or if it showed up in my package manager though

Laptop hooked up to the TV. Always felt more reliable than any other device to me. I also use rustdesk for a remote connection solution

Docker would be my go to