I'm a newbee here, but I have an idea that I'd love to see implemented (if it isn't already and I'm missing it somewhere).
I can see the playlist header being a lot more useful if I could move some playlist-specific buttons to it and out of the context menus. I'm thinking something like having a button to update the playlist order, or having a drop-down to define the playlist's sort-order right on the header itself. I don't know or see if Musicbee currently lets me add list buttons to any other headers or panels, and it'd make a lot of sense to put them on the playlist header itself.