I vote for this too. Though I suspect it's a rather large job. I say that because, using the current file based method, you can map any key to any MCC command. Trying to build that in a GUI friendly way might be kinda tough. It implies a lot of other work such as explaining MCC, the individual commands, etc.
Maybe a more approachable task would be this:
Build a key binding GUI that would allow you to bind a key to any menu item on the main menu, or the right click context menus. That seems like it's a much smaller collection of things and there are no parameters required. Just a one for one mapping of one key to one menu item.
That's probably not a "too easy" job, but seems doable in a reasonable amount of time.
I definitely agree that a key editor in the GUI would lend more polish to this product.
Brian.