2. Separate "Now playing" pane so I can browse in the main page without affecting what is currently playing (lots of players break this). It's basically a separate, anonymous playlist.
3. Support for custom id3 tags. These have been around for decades but only have limited support. Some players do a half assed job, others don't bother at all, some don't even support the "comment" field. MusicBee let's me define tags and use them as columns in the music browser, Now Playing view, smart playlists, searches etc.
That's it. Decent playlist management would be great but I don't find MusicBee particularly outstanding here either. What I'd like is the ability to tag my playlists with the year, moods and comments - like virtual compilation albums.
I don't use my music player for stupid visualisations. I don't care about lyrics or album art. It's 100% about finding music and creating a play queue. If I like the queue I can save it as a new playlist. That's it.