Intersting tool! I can definetely see myself using this in the future.
I must say tho, I was quite confused when I first opened it, no real hints or infos anywhere. Took me a moment to figure out that right click activates the actions, also why is it on press AND release, that seems weird to me...
Support for different/changing time signatures would also be cool!
Also it really bugs me that I can't press space to play/pause ;-; Especially adds insult to injury once you're in the BPM field and Can't Unselect It and when I press space to play, the BPM is invalid and I can have to undo that :((
All in all though, very nice :D