Craving for foods that fake your senses, sounds very much like drug abuse. As growing older I have been striving to avoid potato chips and go for fruits. Apples are sweet and crunchy. Clementine hydrates a lot. Banana provides potassium to avoid cramps, and so on. No junk food provides any of these... Yet, they entice us...
Oh, and the syncthing encryption that you may enable for the folders is for these devices/ clients. This may be useful is you were to use a third part machine, like a VPS, as a 24/ 7 node for your files. That's different from a relay, may be desirable if you want to sync ASAP and avoid conflicts. In any case, conflicts are rare.. you would need to open the DB and add entries at the same time, or some quirky scenario...
Syncthing is p2p. The servers only see your devices IP addresses and let them connect to share data themselves. That's why it's a relay. But AFAIK files only goes from, and to, your syncthing clients; without passing through the relays. At most, the relay may see some metadata as filenames. I have been syncing passwords like this since long ago. Never jumped to Bitwarden because I didn't had the need... May do so anyway because of OTP and Passkeys..
Also, the history of computing is full of remarkable contributions by women (e.g. Ada Lovelace!)
Truenas scale is Debian, if you just use it remotely it may be a good bet. If you may use the server as workstation (e.g. desktop) then you better use Debian itself (or both, as VMs under Proxmox). Managing ZFS is super easy, just create a couple of volumes with small and big blocksize, in either cockpit or whatever web ui. You may also switch OS (e.g. disaster or play around), and recover these effortlessly with zfs import command from CLI. Good luck!
The "simpler" just connect the cable and make it work is feasible, https://shallowsky.com/blog/linux/raspberry-pi-ethernet-gadget.html
GitHub was a social network even before Microsoft bought it, or the bot accounts boosting repos' stars numbers.
Cool. Good luck deploying on new server(s) when the time comes ;)
Hetzner is a great VPS provider that can manage nextcloud for you, check this out: https://www.hetzner.com/storage/storage-share I think it's a great upgrade on privacy with the administration and security being all covered by profesionals ;)
True. And use chroot ;) then you can apt update, etc. If the problem is on the distro itself (e.g. not a failing hard drive)
Etesync maybe?