2. I think something like Project would work better than Space.
4. Does the app need to know its server name? Can it just use relative URLs everywhere instead of absolute? That would simplify configuration.
5. Thanks, I've had a poke around in the DB. I think a Backup/Restore feature in the UI is important. Also good would be a way to request the data programmatically e.g. I'd put it in a cron job before my Borg backup job runs (that would store daily versions using diffs, so it would need to be uncompressed). An "export to HTML/Markdown/[something importable]" feature would help people feel comfortable trusting the app. I have thousands of pages of handwritten notes in an Android app called Squid, and regularly export from that to back it up (it gives me an SQLite DB file only readable by Squid, which is okay but not ideal); without that backup option I'd be pretty worried about losing my work in there, and I get the same feeling about Docmost.
By the way, are you allowed to distribute the Tiptap Pro extensions? E.g. the Latex support and Comments.