I have used Karaoke Eternal before. It does work but you need to use a laptop or something as powerful or else it just studders.

I’m using gluetun with PIA and it works like a charm. Gluetun even has a template on their GitHub.

See these all the time, unfortunately. I just add a line in the torrent client to not download anything with that file extension.

Anything with Sir David Attenborough or Ken Burns

Yes. I run my PC and my work laptop dock (ThinkPad) using a KVM switch. The KVM supports dual Display ports and 4 USB 3.0 ports. I believe I get a max of 4K at 120Hz for both.