1. Jellyseer is what I use, also allows others to request stuff
2. I download via torrents, automated with the *arr suite
3. My seedbox, fast speeds also help with my ratio
4. Jellyfin, just because i prefeer FOSS
5. Jellyfin covers that, if i happen do delete some show then Jellyseer still remembers if i finished it or was only partially done

Lots of seedbox providers offer all these tools with their boxes so you dont need to host anything

check the megathread in the sidebar or fmhy