I’m not expert but for the sake of getting some discussion going:

Don’t open ports on your router to expose services to the open internet.

Use a vpn when torrenting and make sure your torrent client is set to only use the vpn’s network adapter. This way, if your vpn drops out the torrent client can’t reach the internet.

I keep everything local and use Tailscale to access things while I’m away from home.

Plexamp is literally the only thing keeping me with Plex. I probably have less than 2500 songs and it still blows Spotify out of the water for generating playlists. I absolutely love the random album radio and being able to shuffle music by the decade. I find that I actually explore my music more vs just selecting what I want to hear in the moment.