Improved window management

Genode's window manager is very simple and lacks the following functionality: minimize/maximize/restore close window force kill

It seems like the nitpicker service should be modified to support whichever of these functions it doesn't already. I'm unsure of how exactly force kill could be implemented--especially since not all users can be considered trustworthy. How do we fit users into the Genode security model? Users need to be given reasonable authority--complete authority in some cases. Any ideas?