RE: GP GEE BEE
The presence or lack of the dummy radial has little effect on the aerodynamics.
Flaperons are not necessary as the plane slows down quickly as is.
The problem with landings is that it tends to either bounce ( airspeed too high ) or nose over, especially when you hit or land on grass.
So you need to keep up elevator until the plane comes to a stop. Not quite as easy as it sounds.