NGS and HYD L are in the lower right.
It looks like there isn't a dedicated NGS motor controller; instead it is powered from either the HYD L CMSC or the cabin air compressor R2 CMSC.
Running two motors simultaneously on the same variable-frequency drive is considered possible but not preferred in industry; I am not sure whether it's something Boeing does. I would be expecting to stop the motors, rearrange the contactors, then restart the motors.
As for vacuums... remember it can't be 3000PSI of suck; suck isn't a thing. It's ambient pressure pushing in. At sea level you have ~15PSI of air pushing the fuel into the pump; at altitude it might be 7-8PSI. You don't want a near-perfect vacuum on the fuel because then it starts to boil on you.