I don't recommend Debian for Apple Silicon, just stick with Asahi Linux. There aren't any big issues, except the fact that not all Docker images are built for arm64.
Andromxda
I use self-hosted draw.io together with the Draw.io Nextcloud integration for a diagram, and Wiki.js to write down some important information. If you prefer something lighter, check out DokuWiki. There are many other options for a Wiki like Bookstack or django-wiki.
You can download individual books through IPFS, but not a collection of their entire dataset
Not exactly self hosting but maintaining/backing it up is hard for me. So many “what if”s are coming to my mind. Like what if DB gets corrupted? What if the device breaks? If on cloud provider, what if they decide to remove the server?
Backups. If you follow the 3-2-1 backup strategy, you don't have to worry about anything.
Media corporations try to pressure us into thinking that piracy is stealing
You can switch to the WYSIWYG Editor in the settings
I've been using TubeSync, but I switched to Tube Archivist. Works very well, I'm happy with it.