RE: mini edge 540 help!
you will be able to use a 4 channel set up on most planes as all you need is the obvious 4 channels.
1 throttle
2 rudder
3 elevator
4 ailerons
All that 6 channels will enable you to do is to electronically mix different channels together such as two seperate aileron servos together to mix them so you can use them as flaps as well.
many other mixes & functions are possible such as retractable undercarriage, flaps, bomb doors, - the more spare channels you have, the better.
But if all you want to do is fly it normally, then a 4 channel set up will be adequate.
A lot of planes use 2 servos for the ailerons (one on each wing) so you will just have to plug them into 1 socket in the receiver by means of a "Y" lead to join them together.
Regards Craig.