I got it all to work with some notable problems:

1. I can't get the airbrake on any control other than the throttle stick. This is going to cause a problem when I think I am hitting the throttle while in fact I am hitting the airbrake! I can get the ESC, plugged into CH3, on the D slider
2. I can't get the specified throws on the flaps and the elevator.
3. I can't figure out how to set up the AIL->FLAP mix so that the flaps travel half as much as the ails, which in turn have 2x the up throw vs. down. The setup screen is too obtuse.
4. The flaps are not controllable in isolation, only as part of a mix!??

(I have set up using the GLID2 framework, with flaps on separate channels)

Now a hardware problem. Multiplex and Castle say their BEC won't support 6 servos ... thermal overload problem. So I have to use a third battery (already have a second one, 12V for video), or a separate BEC. Given that the flaps are very seldom used (only for butterfly and a slow/speed mix), and the fact that I will be flying straight and level most of the time, is this "thermal overload" problem for real?