I run a Jellyfin server and then have a nvidia shield with lineageos installed directly attached to the tv with Whole installed on that. The shield remote works perfect, nothing connects to google/elsewhere unless I want it to, and if you wanna get fancy, you can always do a full/semi-full *arr stack, wholphin can connect to Seerr to request stuff so you barely need to touch the back end unless something goes wrong (I believe there are a couple of “public” jellyfin/Seerr servers but I’ve never really meased around with them, but that would eliminate the need to run a Jellyfin server for yourself. If you do end up going that route shoot me a message and I can see if I can find the addresses for the “public” jellyfin server)
Also worth noting, you should be able to install wholphin and try out jellyfin with your current setup without needing new hardware immediately, that way you can see if it’s for you before buying a Shield /something else
Seerr doesn’t download torrents from JF, it adds a request to either Sonarr or Radarr (which grabs the torrent from an indexer, adds it to your torrent client, then when it finishes, moves it appropriately, and let’s JF know that there is something new, and tells Seerr that it finished)
You basically set up a regular *arr stack then put Seerr on top of that. As long as you set up the underlying *arr stack correctly, then you should be able to minimally touch it and everything should be fairly good on its own. I open my underlying stack about once a month to clear out any weird issues, but I could go longer if I wanted.