Yea, same thoughts. That's the first thing I would change if building a Kaos, especially this size. I kept the existing airfoil but reduced it by 20% - in a drawing. Not sure how well it will work but there's nothing like experimentation.

Matt's ideas for the spars strike me as good ones. The balsa becomes redundant if using CF. Another option would be to use hollow rectangular or square sections of CF. It strikes me as it would make a massively strong wing. In the much smaller wing I drew up, I went with spar doublers in typical Japanese MK style. The spars are thin but they are doubled for about half the panel span. The joint makes them very resistant to bending as the grain is locked in place by the glue so they can't slip with respect to each other.

Another very cool wing building design concept is to use interlocking shear webs (see last picture). The webs lock the ribs and spars together practically without glue. The webs also produce the dihedral required by design. With a flat top wing, only the bottom of the webs would be tapered while the top two corners would be at 90 degrees. I think the easiest way to build a Kaos wing is to build it inverted flat on the table with the rib center lines parallel to the surface.

David.