I will definitely be looking into the BEC amp rating on my next ESC purchase, all are good points. One thing I would like to add as well. Once powered up, servos even at a static centered position still pull amps to hold that position, very little compared to full deflection, but do require power nonetheless. I think with my Bushwhacker I am pushing the limits, mind you the Flaps servos are 5g and no 9g might help a bit. The label has been removed from the ESC but I still have the manual for it so I should read up on it.
Some good servo/BEC education here, thank you.