Reassigning Mission Control function keys

On my Apple wired keyboard, the F9 to F12 function keys are assigned to Mission Control, Application Windows, Show Desktop, and Show Dashboard. I would like to free up all the function keys to use for other things and I know that I can do that by unchecking those functions in Keyboard Preferences under the Shortcuts Tab, and Mission Control setting. But that does away with access to those functions, unless I reassign them to other function keys, which I don't want to do.

Although less frequently used, I would like to still access those Mission Control functions from time to time. I was wondering if they could be assigned to a key combinations, perhaps using the Fn key. I tried re-assigning them in keyboard preferences to a key combination but it will only accept one of the function keys with no modifier.

I know that I can get around the problem by assigning a key combination to launch the Mission Control view (all windows open) and Dashboard and then using the Escape key to get out, but is there no other way to access the 'Open Application Windows' or 'Show Desktop'?

I have Quickeys and Karabiner so I can assign key combinations, but I need a destination for those key commands to go to. Could anyone tell me how I could access the 'Open Application Windows' and 'Show Desktop' other than by using function keys?