1. any switch will work as long as the wires are in the correct order and it has the correct plug, it is pretty universal now

2. digital servos will use more power, 1 good 5 cell rechargable pack is recommended

3. you can use either of the crystals with no problems, if your channels were something like 68 and 90 you might see some slight glitching problems but since your are fairly close it should be fine. technically it is supposed to be retuned according to FCC regs but nobody does it.