Wont go inte networking, but assuming networking works between them you can manually specify an IP in the mobile app:

Add a device -> three dots in top right -> add devices by IP.

Bonus: This also works over tailscale and similar apps, making it so you can have an always on connection despite not being home.

If your data is very important you should definitely prioritize implementing your backup for at least the most important stuff. You could probably move it over, but in case something happens your data will most likely be gone, or best case very hard to recover.

Fedora is a great distro, but they are decidedly bleeding edge on purpose and IMO not the best choice for a server hosting critical data.

A better option would be running a hypervisor like proxmox (you can even convert your existing Debian install, but I havent tried this personally) and passing your GPU to a virtual machine that runs fedora.

This gives you both a very stable environment for your data and and a bleeding edge environment where your hardware decoding likely works great. I do this exact thing personally and it works great.

Seems to be some cursor themes that do it that way, like this one for example: https://store.kde.org/p/2103612

Yes, its possible to check. Data has to be sent through some connection, and we are able to monitor all traffic going through connections we control. Its not happening on wifi and not on 4G/etc. So unless there is some other connection that is not a real issue.

Arent they owned by a Chinese company these days?

Have you tried tumbleweed? As someone who uses both Fedora (or more accurately Nobara) and tumbleweed, my laptop experience on tumbleweed has actually been slightly better on tumbleweed.

My only remaining issue is that wayland has slightly more input latency when playing games, enough that it’s noticeable (or a very convincing placebo effect).

This makes it so that I have to use X11 and that I have to disable compositioning when playing games as my displays have different refresh rates. All in all, not a big problem but looking forward to be on wayland for good soon.