Some keys/shortcuts don't work in 12.1, GNOME 3 fallback mode


I’m on openSUSE 12.1, GNOME 3 fallback mode. How do I make:

  • “Delete” key to delete items in windows & on the desktop
  • Mod4 + D to minimize all windows in the workspace

The latter in 11.4 was easy: system - preferences - keyboard shortcuts - Hide all windows…
But I have no clue how to do it in 12.1.