Comment 1 for bug 1196164

Alt+click to move a window is almost universal across FOSS desktops and has been for ages. IMHO Chrome should be embarrassed about that one.
Alt+F4 to close a window works across most FOSS and non-FOSS desktops.
Alt+F[789] have been the norm in Gnome and now Unity for quite some time.

Changing Alt+F4 would probably be the toughest sell of all because it bridges into non-FOSS compatibility and user expectations. I don't see how keeping Alt+F4 but making F[789] inconsistent with it could be anything but a step backwards.