Yep, all of those things, with a Synology NAS for storage running in docker containers on a laptop in my office. When it worked, it was seamless. When it worked.
I think for some folks, maintenance is part of the "hobby" so they may not think of it as a chore, but I'm at a point where I don't really enjoy the sysops stuff as much anymore.
Agreed. I run that same setup on a Synology NAS as well, but hassle-free, it ain't. Full coverage doesn't even exist anyway. Unlimited + 2 block accounts still misses plenty of Rick and Morty episodes, for example.
That said, this setup has allowed me to cut out Netflix. I still pay for the Hulu/Disney package for live sports and some animation shows that aren't available on Usenet forums.
Plex Metadata Manager also allows you to import tmdb/imdb/tvdb/trakt lists which makes discovery a solved problem. You can have it import the top TV shows and movies currently playing which means it always has the latest releases.
The whole process is absurdly low maintenance once set up, as long as you have the storage space for it.
Plex/Sonarr etc don't handle the actual downloading part, so they don't need to be behind a VPN. They simply look up the show metadata from public databases and find downloads available from indexes you have registered, passing on the download that best fits your criteria to whatever download client you have configured (so the download client is the only part that needs to be behind a VPN).
No need, you can sign up for any of the hundreds of private torrent sites and the RIAA isn't legally able to join and send anything to your ISP, and without literally the RIAA sending the letters to your ISP, your ISP doesn't care.