The help screen could have been generated from Lemur's input mapper (though it wasn't for time reasons and because I didn't think of it).
Lemur's InputMapper was precisely written for the reason that being able to remap things should be easy and 'reflective'. I have not written a UI screen for configuring these yet but the calls to InputMapper to switch keys or add new mappings is really simple.
You can see how the movement defaults are setup here (which was cut-and-pasted from Lemur's camera movement example, actually):
...though lately I've taken to checking to see if the mapping exists before setting up a default so apps have more flexibility of when they override them.
As of this weekend's commits, Lemur has that. It will be in the next release in some form.
Bunch of stuff related to that pending in the next release:
But as it stands, I can navigate the SimEthereal example with tab/shift-tab, cursor, joypad, etc.. I think I specifically mentioned it in the post above.