In a few minutes, using just the features that you already have, you can create a 3-function shortcut key. From a Metro app or Start screen, press the key once to switch to the Desktop. Press it a second time to minimize all the windows. Press it a third time to reopen them.
Go to this folder:
C:\Users\Default\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch
There you will see the "Show Desktop" icon. Copy and paste it into
C:\Program Data\Microsoft\Windows\Start Menu\Programs\Windows Accessories\System Tools
Then right-click it there to get the "Properties" dialog box, and assign it a shortcut key by typing that key in the "Shortcut Key" pane.
When you use the key to switch and peek, you can use it alone if it's one of the F1-F12 keys, or one of the four keys + - / * on the numeric keypad. If it's any other key, you have to hold down Ctrl + Alt while you're pressing it one or more times to switch and peek.