I think that this is a way more interesting and pleasing shot than many which finished higher. The technical points about flashes and shadows should not have brought it down below a stack of basically boring shots which did better.
need to reduce the shadow caused by the frontal flash. Try to use the flash off camera at and angle & use a reflector to fill obvious shadow areas.
Also your subject is too near the background. Try moving him away from the background say (3-4ft away) then select the right DOF to ensure the background is blurred.