Qole - quick thought;
in your next edition/release.. any chance you could make debwm take 4 arguments, and change xpice to something more generic (startwm) and have it take 2 arguments..

debwm IceWM startwm IceWM icewm-session

this makes it dynamic.. your shortcuts and stuff will still launch iceWM by default.. but this makes it so users can simply add their own menu icon by running:

debwm xfce4 startwm xfce4 xfce4-session

The code would look something like this:

There might be a way to clean that up a bit .. obviously the first and third arguments need to be the same as they both represent the window managers title.. if there was some way to pass that title using just the first argument would be nice but I haven't tried any of this on my table.. i might do it while I'm bored here at work though..