Steve, I agree with most of what you said. I did not remove the cut-outs on mine and covered one side with light weight glass. I also added pieces of 1/8-inch balsa and a couple of triangle stock gussets linking the cabiane support to the LG plate that extend about 1 1/2 inches over the wing saddle doublers. Have not had any problems. As far as power off glide, it's not great, but I think pretty typical of any draggy biplane airframe its size and weight. And as far as bad landings I'm the freakin' king, I've bounced so hard it's gone back to pattern altitude!
How does the 3 blade work, the 15/8 on mine mows the lawn.