

The applications aren’t that good. That’s the only thing keeping me from switching completely. Subtitles, aspect ratio, audio track selection just don’t work as expected. In some cases I can only pick the aspect ratio and no subs and sometimes the other way around? Also if I have no subs for a movie, I can’t search for them on the fly - good feature of plex. As it stands, jellyfin video player is not up to my standards and I can’t switch yet. I use it for porn though. That works fine.
Simplest is to use syncthing and just sync everything to your phone but this won’t cover a lot of your use cases and is probably best for a one user experience.
Lidarr for new music + a subsonic server such as gonic will cover a lot of what you need. The idea is to find and download music(lidarr+dl client) and run your own streaming server(gonic or other implementations). On mobile you use an app which supports the subsonic protocol (such as substreamer or tempo) too listen. You can also just use jellyfin server + it’s client, but AFAIK, the music experience is not as good.