RE: Help with 1st giant scale
Depending on the model receiver you are using you may not have enough spare channels available to do everything.
I would get a matchbox and plug it into the aileron channel and then plug all 4 aileron servos in the matchbox and adjust each of them.
You can use the elevator channel and a spare channel to mix for the elevator servos and you can use the rudder channel and another spare channel to mix for the dual rudder servos.