I would like to be able to easily discover what key command combinations are available when trying to find a suitable command. Perhaps, right click in the “Type in Key:” field and have a context window pop up to choose from. Seems that since Alt, Ctrl and Shift seem to be the only keys that can be doubled, the list of possibilities would not be too long to display, and if it is to long it could be built accordion style. It is clumsy just trying to peck around to find a suitable and available combination.
There’s load of possibilities… Personally I’d change the old ones to suit you. Have a look at my table. What a fight making it was, it changed me white from grey. Anyone working with Word in such away will know exactly what I mean.