Been using ubuntu for almost 15 years. My annoyance with snap made me just switch to bazzite (gaming focused fedora atomic ). Takes a little getting used to since its immutable but im liking it alot more so far.

Serverpartdeals.com

Factory refurbs. I have 3 nas boxes full of drives from there. No issues

I think you can generate static html reports from tautulli

Joplin server also will use a file based storage instead of the db. And db then is only used for users

I use joplin as i share notes and collaborate with my wife. Obsidian etc dont do that. Id love to be on obsidian as i really like it but sharing notebooks is mandatory