RE: trailing edges
When I see a plane built with a squared off trailing edge, the first thing that comes to mind is that the builder is lazy. It looks unfinished and just plain WRONG. The majority of ARFs are built that way. Do you think they are concerned with aerodynamics? Hell no! It's the good old $$$$$$$$$$. It's cheaper and faster to leave the control surface square. I'm sorry to say that this is the way that many modelers view it also. Slap it together, cover it fast with plastic wrap and get to the flying field. No sense of pride in workmanship any more. When was the last time you saw a full size plane with rectangular shaped control surfaces? NEVER! We fly in the same air that full size planes use, under the same air flow conditions and surface loads. It has to do with smooth air flow and aerodynamics. Before you know it, there will be larger models with nothing but a plank for a wing, like the foam electrics use. They don't fly, they are dragged through the air by the power of the electric motor.