Firefox doesn't respond to a shortcut for window zooming, because it has another "zoom" menu item, how can I avoid this?
Firefox uses XUL files to define its user interface on all platforms. I just did a little poking in my Firefox.app 4.0.1 bundle:


The XUL files are stored in Firefox.app/Contents/MacOS/omni.jar. (jar files can be unpacked with any Zip  archive tool, or the jar command-line tool which takes options like tar.)
The relevant XUL file may be chrome/browser/content/browser/baseMenuOverlay.xul. See also the referenced DTD files for the definitions of the entities like &amp;zoomWindow.label;.


Since you're editing the files anyway, you might as well add a shortcut there rather than changing the name to use the system shortcut customizer.