That's great. There's definitely an overlap of astronomy and amateur radio interests, and anything you can do to generate and feed the interest of young people is time and effort well spent!
Obsidian saves in markdown format, and can import your OneNote in one shot.https://help.obsidian.md/import/onenote
I remember running linux on a Sega Dreamcast. It didn't do anything, but I had fun doing it. I didn't have the network cable dongle.
Yes my Plex server is a W520 and it shuts itself down at night because it's in the bedroom and the fans are too loud.
That's great. There's definitely an overlap of astronomy and amateur radio interests, and anything you can do to generate and feed the interest of young people is time and effort well spent!