Is there anyway I can make it so that I can still switch between apps while playing a fullscreen Desktop game? (ones that aren't from the Windows 8 store)
Yes, I tend to do this all the time. The game has a option for windowed mode which allows you multitask like StarCraft II but just need the hardware to run multiply things. Sometimes its windowed mode without borders.
If the game does not have it in the options then your out of luck but most modern games do have it.