The inverter will power the outside fridge, which we haven't used, while you are on the road. I would not run the inverter unless coach engine is running, it pulls a lot of juice from the house batteries in a hurry. Since I haven't used or needed the inverter I'm not sure what else it powers. With the crappy Harris batteries it won't last long.
You can email Thor and ask for the build diagrams for your coach, they will show how everything is wired, plumbed, etc. I emailed Thor on Tuesday and got all the drawings on Wednesday, pretty good customer service in my opinion!!! Never know when the drawings might come in handy!
On weekdays you can call and ask, they have always been super nice the couple of times I have called!