Im running a similar setup (ZFS pool, Cockpit, portainer x2, and a few LXCs for Plex, Frigate, etc) and it’s been great. Before building it early this year, I’d been running everything on Windows for the decade prior because I was unfamiliar with Linux and struggled like OP when problems arose, but after following a guide to get everything setup it’s been rock solid and if I screw anything up I can just load a backup. I’d also looked into TrueNAS and Unraid but this gives me a more flexible setup without any extra cost and the ability to tinker without affecting anything else like you said.