I didnt strenghten the Cabane area, but wish I had done. It held up OK, but I was always concerned about it. The problem was that the bolts sunk quite alot into the lightply. I would have though that 1/16 would prevent this so would go for it.

You are right about the back wing bolt. I didn't like this either, so I used one of the smaller lightply cut outs from the fuz to make a plate which I glued to the under side of the wing before drilling through.

I had a YS 120 in mine. Watch out for the weight and balance. I made a hatch under the cockpit and put the radio gear in there to help balance the engine. I made the hatch from the lightply cut out for that part of the fuz, just sanded it down a bit so that it would fit easily. Still had to put two oz at the back, and that was with the rudder servo out back as well.