RE: .40 SIZED FLYING WING
CP,
I have tried using composite torque rods a couple of times and they were a dismal failure. Flutter and very elastic response was a constant issue with them due to how they are made. Perhaps if ones were available that were bi-directionally spiral wound around a longitudinal core it would be worth a shot.
As far as the solid TE I would think that that is a must given what you want to do.
Using the 1/16 balsa over a foam core with a bit of carbon added to the foam may be something you may want to try to stiffen your wing a bit...