Doc it's been a generally accepted idea that a thinner elevator makes the airplane more stable (less touchy on the controls around neutral) so that the airplane flies more in a groove without fidgety jumping with tiny unintended hand movements.  I too still subscribe to that idea.  Making the stab thinner would simply lessen that affect.  I don't know what you are building but it also could be the 1/2" thickness is for rigidity and warp resistance.  There is a new thread here mentioning control surfaces being thicker that the trailing edge.  My inclination is to believe this would make the airplane quite responsive, but to a fault in our application.  Boundary layer re-attachment would be immediate and positive even with controls deflected.  Those surfaces would respond as more effective but you might not care for it on the control handle.  See ya soon.

Dave