Re: Gimp

> >>  (when (featurep 'w32-regdat)

Change this when to if, so that you can use an else clause.

> >>        (reverse (cdr cmd-list)))))

Change this to:

        (reverse (cdr cmd-list))))
    '("gimp-remote" "gimp"))


AFAICT, this initialization is the only OS dependant part of your code.