1) Unless there is some weird limitation I don't know about, shouldn't numbers be allowed as hotkeys too?
2) How about a keypress detector for the hotkey dialog? So it says "Press your key", you press it and then check off the modifiers (ctrl, alt, shift).
3) Somewhere on the hotkeys changing screen, it really should say that the changes won't take effect until you close VLC and open it again.
4) A "this key is already in use" checker would be nice as well.
Just a few things I observed while working with hotkeys this week.
Thanks