*Why would the elevator need more servo power than the rudder? My experience is exactly the opposite for non 3D flying.
Technically you dont, but if you use a single servo for the elevator, it has to be mounted in the fusealage with a long pushrod. With a larger size bird, this will flex while "pushing" the control surface, producing undesireable results. With two servos, you elimintate this because they are mounted very close to the control surface itself, and you can tune each elevator to be exactally the same as the other, for optimal performance.

*Is hand starting the norm for gassers?
Yes, although with the 50 cc class, and maybe some 80-100cc you can use a starter with about a 4-1 reduction pully assembly to acquire the appropriate torque to turn the motor.

*There are several 40/50cc engines available. The Fox sure looks good. Why doesn't it get more press?
The fox motor is fairly new, and fox is mainly known for their glow motors. I would definitely reccomend a BME 50, or a DA 50, I have run both and they are completely awesome! the bme is a little lighter than the DA but the DA produces tons more power!!

*With 6 bolt prob hubs, how do you drill the prop?
The motor company that you buy from usuially will sell you a prop jig to drill all the holes relatively perfectly. Desert Aircraft stocks one that works very well, but i am sure you can get them elsewhere as well.