Here’s a nice picture of Winamp in all of it’s glory. Left side is my media library, right side is my playlist. I’d like to see something similar when I’m editing a regions playlist. It’s just nice and compact, lets me see a large playlist.
So maybe a split view on the region playlist editor (media on left, playlist on right) with drag n drop between the media library and playlist. Any edit/delete etc on the playlist is shoved into a right click context menu.