For bulk diverse, pre-tagged and sorted collections you really have to go to p2p like soulseek.
For tagging picard is really the only option that can handle bulk tagging with some level of trust and authority, but definitely have a backup or work in chunks just in case it goes awry.
For a spotify replacement, Plexamp is really doing well as long as you have decently tagged media. It can do all the mood radio and playlist suggestion stuff that Spotify and others have been doing.