It seems the charge jack is diode protected, just like many older Tx's, so the charger cannot detect any voltage at the terminals, but it can be charged by a "dumb" charger like a trickle wall charger. I just need to disable/override the charger low voltage detection to make it work.

As for the servo driving not working - Oops - It works fine when the servo is plugged into the correct port! DOH!