The Keyboard shortcuts dialog is full and new shortcuts can not be added at the top level without removing existing shortcuts. Keyboard shortcuts allow a subkey relationship to be manually created but not through drag and drop. It would be convenient to allow shortcuts to be dragged and dropped under other shortcuts so that you can easily move existing shortcuts to be under others so that you can add new first-class items. For instance, I would like to drag all shortcuts for Accudraw keys under the A shortcut, all Snaps to be under the S shortcut, etc. Of course, the parent level cannot have a key-in associated with it as is currently the case with the sub key-in system.