Yes, I’ve installed e/os on my fairphone 5 and it just works. I even got my banking apps to work.

Not really unfortunately. I use Joplin with my notes living on my nextcloud at the moment, but its still not quite what I’m looking for. Notesnook might be another one worth looking at. I think you can also self host it, but I haven’t tried it yet.

https://notesnook.com/