Bob:

I noticed I did not address the tapered/nontapered surfaces.

A nontapered surface with a sharp edged blunt TE is almost as low in air drag as a tapered surface with that same hard edged blunt TE.

If you can make the taper greater than a 4:1 ratio, and have a genuine knife trailing edge, you will get minimum drag in level flight from the control surface. The 4:1 ratio means, of course, if the surface is 3/8" thick it would have to be 1 1/2" chord.

But even if you start with a knife edge, it wont be that way long. Or you will spend all your time protecting it.

With the knife edge, the upper and lower boundary layers separate evenly, with minimum vortex generation.

A rounded TE aggravates turbulence, giving lessened control effectiveness.

A sharp cornered blunt TE greatly decreases the induced turbulence and vortices affecting the control surface.

So. If you want to taper the surfaces for appearance's sake, do it. I do it too, and for the same reason. But if you build two planes. identical except having tapered surfaces on one and flat surfaces on the other, you wont tell any difference flying them. As long as you have the hard corners on their trailing edges.

Bill.