I have been following this thread, because you never know when you might learn something that may save you from pulling one's hair out!LOL!!

If you are using a regulator between you battery and switch, pull the thing and try again with out it. I built 2 new planes, decided to use 6 volt batteries, with a regulator. Bad idea, both planes went nuts, I had tried everything, down to changing each servo one at a time, I pulled the regulator and both planes have been rock solid. If you haven't considered the regulator, try it, and I hope it works!!

Dale