Hi Lennart

>
> Use define-minor-mode and make a global minor mode. Define your key
> bindings there.
>
>
Thanks define-minor-mode is an idea ... but IMHO wouldn't help when
extending major-mode keybindings ...


>
> > c) attach documentation  to them
>
> Documentation are bound to functions, not key bindings. (You can add
> comments where you bind the keys, of course.)
>
>
actually according to `define-key' documentation the DEF part in a keymap
can hold much more than just a command, such that it should be possible to
associate meta informations to a key binding.


Cheers
  Rolf