RE: Adding weight
There were a number of pattern planes that were designed to be heavy, I have one of the old designed Daddy rabbits that was designed to come out heavy just to compete in different wind conditions. Adding extra weight isn't the best idea but in most planes that had a rotary engine they are going to come out tail heavy every time. I have built Bipes that left no choice. Sometimes you just have to bite the bullet and grab the lead even after you have moved all your gear up front. You do what you gota do.