Can you also remove the "Available offline" button?
It happened to me that I presssd it a couple times, then I had to resync my music again. I didn't had any connection, so I was out of luck at that moment (I was in another country at that moment)....

Maybe you can put that button into the playlist screen:
Hold down a playlist, a menu will popup with 'Available offline' or 'Unavailable offline'. (After selecting the option, adding a 5 second timer is also a good idea just in case...)
Also, the ability to remove playlists would be nice too you could also add this into the menu when you holddown on a playlist.
Again, when you press Delete playlist, a 5second timer for cancellation is also needed.