How's about you lose the navigation bar and change the down swipe to show the gesture screen and the up swipe to show the applications. The graphics employed here - in my view - make the UI tacky. Real estate is wasted on a widget that shows which screen you are on. This can be done in SO many more subtle and less intrusive ways.
Dropping the navigation bar would allow your UI to look clean.
Because of the gestures - which is the killer tool - I don't need any shortcuts on my desktop anymore. In fact, I don't even need virtual desktops. I know this is my preference, but surely these options could be defined by the user in the preferences screen.