Is there an application to identify the configuration driving a system-global keypress

Solution 1:

• Fn× handled by BIOS/Firmware or driver.

  Some vendors provide a way to customize them with limited options. If you are comparing with MS Windows, some vendors supplies tools with their binary drivers that can talk to BIOS some how.

  If it's handled by driver, See How do Fn keys work? or precisely Linux And Samsung Series 9 Laptop Fn Keys. Dell laptops uses dell_wmi kernel module. Look for other driver in the same folder.

• CtrlAltF× are console keys that need to be handled in the early boot stage. Try January's answer in Change Default TTY shortcut.

• General Window Manager shortcuts like CtrlAltDel and Media keys Print. Most are handled by media-keys plugin from unity-setting-daemon package. They are stored in dconf database.

  gsettings list-recursively org.gnome.desktop.wm.keybindings
  gsettings list-recursively org.gnome.settings-daemon.plugins.media-keys
  

  or

  dconf dump /org/gnome/desktop/wm/keybindings/
  dconf dump /org/gnome/settings-daemon/plugins/media-keys/
  

  I used to search dconf blindly, example looking for Print key:

  gsettings list-recursively | grep -i -e print
  

• Unity shortcuts Super and other window management key. Currently, Ubuntu using Unity as a Compiz plugin. So its key bindings are stored within Compiz settings.

  ccsm → Advanced Search → Check Settings value: key name ex. super