What are the best practices to keep umbrel up to date? Run apt update && apt upgrade every now and then, or only updating via the web interface is enough in terms of security?
Ideally you can do everything you need to right through the UI, from updating to managing your apps. In the app store you can update your apps and System > Check For Update to update Umbrel. I’ve never really needed to go to the command line, unless I was trying to configure something more advanced like a new feature.
With the new automatic recovery tool, you can restore from your most recently dated automatic backups too, here’s how that looks: https://twitter.com/umbrel/status/1562099972547690501?s=20&t=Tag86rox8mNolXiq9wT-zg
For your seed phrases and wallet backups, it’s always good to have those in order and to each his own on how best to secure those. Anything from a seed plate to whatever you think is the most responsible way of securing your local network and backups! (Also, it’s good to eventually get a new SD card in case your original fails in 6 months - 1 year).