I would agree that model airplane designers must have a list of "do's and don'ts" that they follow. Whether it was derived by experience or by formulas and calculations, I don't know. I wonder if full scale design is a one to one corrolation to model design, or are there some scaling effects to take into consideration. I'm sure the info is out there somewhere.

Setting a target wing loading would be hard because its hard to predict what the finished model will weigh, at least for me, but maybe close is good enough. Its fairly easy and cheap to experiment with models but I'd like to be "in the ball park" when I start a new design intended for a single purpose, like going as fast as possible in a straight line.

Ollie,
One could argue that a 34" x 5" wing at 2 degrees AoA would have the same amount of drag as a 30" x 5" wing at say 4 degrees AoA? No?
I agree that a high aspect ratio (HAR) loses less speed in a turn than a low aspect ratio (LAR) and a LAR wing is faster in a straight line than a HAR wing. Just depends on what your after.