I have a similar setup using Truenas to store data. I've setup a VM in Truenas that can access the data via NFS (easier to setup on Linux than SMB).
It's nice to keep all your services contained in one machine, as long as it has enough resources, and will probably consume less power than running another PC.
I use qbittorrent, most people seem to agree it performs better than Transmission. It's accessible from a web interface.
RAID5 is risky on drives that large, there's a decent chance of a read error during a rebuild.
RAID6 will provide more protection but you lose two drives worth of capacity to the parity data. I'm not sure if a three drive RAID6 is actually possible but a three way mirror would be more sensible as you'll avoid the extra computation of parity calculation.
Imo RAID6 starts to make sense in an array of 5 or more drives.
I just tried adding a native VPN and there's no option to use Wireguard
You should try out KDE in a Live CD. The snapping and tiling features work very well, Windows needs to catch up
Pinhole has allowed custom local records for a very long time now
My method to get around this is setting up a specific user account for my TV. In the user options you can disable transcoding
It is paid for, with your time ;)
Jellyfin? It's always supported 4K afaik
It depends how valuable your data is, what backup strategy you have, and how long you're prepared to wait to get access to your data when a drive fails.
Personally if/when I migrate my main dataset to SSD, I'll stick with RAIDZ2/RAID6.
I came to Arch for the customisation, I stayed for the AUR
It sounds like this software was made to address a problem that exists in Windows, poor window management options. Although with Win11 it's been significantly improved.
Have a look into tiling window managers, or tiling add-ons for major desktop environments. You can split windows in all different arrangements without any extra software or splitting inputs.
Personally I'm using KDE and it's built in tiling options work very well.
Like the others, I suggest you stick to a distro designed for desktop use (Ubuntu, Fedora etc), you'll have a much easier time.
If you really want to go with something closer to "scratch made" I'd recommend Arch. Its documentation is killer and you can build a system suited to your requirements.