Lets start with the back up camera. Are you wanting it on while just siting or with motor running. If just sitting I do not believe it will come on. As for when coach is running a lot more info is needed to help, the model of display that type of thing.
No the slide does not need to be out for ac to work.
The remaining items. Are you plugged into shore power or not? Do any of the 12v items work, i.e. lights that type of stuff. My first thought was the battery disconnect switch was in the off position. Then I re-read and you said the batteries were turned on. When you move the disconnect switch do you hear a clicking sound? If not maybe the switch is bad.
You most likely have more than one switch for the water pump. does it work from any of the switches? There is an in line fuse somewhere near the pump that may not be any good.
Good Luck
