RE: old dawg looking for answers
Without knowing that brand, I'm guessing that it is a 45 amp ESC with a BEC built in. I'd goolge the specs on it and perhaps you will find it has a Max of either 3s or 4s for battery cells. Then depending upon your motor and prop choice you could use 3s for sure and maybe even 4s if it is within range.
The battery will power all servos and esc,motor thru the one connection , but your welcome to use a seperate BEC instead and disable the built in one. Most esc are programmable thru the TX , but may be cumbersome. The program card will make it a lot easier to program and if you can get the program card I'd get it.
Do some googling on that particular esc.