RE: trailing edges
All of this talk about rounded TEs causing turbulance is 100% true..... It has been tested on full scale and it is proven to cause flutter. I personally can not tell you exactly why.
Does this apply to modeling is the real question. I am not so sure that it does. Most of these models have a relatively thin airfoil AND typically are not flown extremely fast. For these reasons, I think the RC world can get away with rounded TEs. I mostly build giant scale aerobatic planes and leave the trailing edges squared off...... everyone is entitled to their own opinions, but it is not due to laziness and it does finish the plane off very well.