Is there any way to modify the "Widget Dashboard" settings so that you can exit the dashboard by simply clicking on any available whitespace (i.e., an area on the dashboard that does not have a widget installed)?

I know that you can click the little red "x" at the top -- or hit the Esc key -- but both of those are time wastes. It would be great if you could exit by simply clicking an area.

I'm afraid this isn't possible at this time - it would require code changes to the widget dashboard in order to be supported by Plasma Desktop i'm afraid.