For work, we use Bookstack, you can use the api to export pages as markdown as a quasi-backup. At home, I have been using Jotty. It saves as markdown, organizes with folders, and has a decent mobile interface for when you’re on the go. I just use syncthing to sync the data directory (markdown files in folders) to my backup storage
Good write-up
TrueNAS (ZFS) needs direct access to the drives. Typically a software raid is considered to be more reliable/flexible since with ZFS it also checks for file integrity. You can set several variables to add to the integrity as well as special vdevs to help speed things up. Integrety comes at the cost of storage, so make a plan for how much storage you need versus how much data integrity you need.
Personally, I really like dnf over apt, SELinux over apparmor, and firewalld over ufw, but it’s all personal preference.