I thought about placing elevator servos in the tail and may still do that yet,however,after reading this thread and the out come of this model seems to have a tendency to be tail heavy i fitted servos in the standard location untill its all fitted up ready for ballancing and will see from there wether its a viable option as i naturally dont want to add any additional weight if possible.
Crikey,1.5 - 2" of tube in the wing would be an accident waiting to happen for even basic flight.Can well understand your concern there.