That would explain the balance being off so much. With that light Saito in the nose, and all that stuff in the tail, you have a very tail heavy plane. If you could move the rudder servo to under the canopy and do pull pull that would help. If you wanted it to balance with minimal nose weight added, you'd have to move all the servos to under the canopy and go with CF pushrods and/or pull pull. Or if you left everything as is and went with gas engine in the nose that would balance that plane perfectly.