If you have a metal clevis on the throttle link replace it with plastic. You might want to try and re route your receiver antenna.
while I balance my props, to have an ubalanced prop cause a crack in a receiver board the airframe would fail before the board would crack.
If I read your post correctly you tired a different transmitter and got to 20 paces? that says your orginal transmitter may be weak and needs a slight tweek. send it in for a look over