Have you checked tailscale? a one click wireguard, free for quite a lot of devices. there is a project to selfhost the control server https://headscale.net/

I’d try to stick to the official recommendations to backup immich: https://immich.app/docs/administration/backup-and-restore/

If you work in IT you will love it. If you work for a company and understand IT jargon you will enjoy it. If you have no connection whatsoever with IT you won’t make the first two chapters 😅

Currently reading The Phoenix Project after postponing it for months, I finally found time during Christmas. So far i’m liking it, though you need to be connected to IT to enjoy it.