It would be convenient to be able to navigate (and assign a hotkey) to the previous bookmark. This would make bookmark navigation and difference navigation symmetric.
Also, paging through key assignments one at a time is a pain. It would be helpful if when using the hotkey assignment dialog box, an attempted reassignment of a key combination would refuse to take that combination AND would jump the command list to the item that is currently assigned to that combination.
[closed] Navigating bookmarks...
You can check this at current beta at http://www.grigsoft.com/wincmp3b.zip.