RE: 1,000 Watt Inverter Install
Let me second Dennis's comments on this. A 1,000 watt inverter, if you were
actually going to pull that much out of it, is going to draw at least 80
amps from the battery and probably much closer to 100 amps, one hell of a
load for anything but the heaviest wiring.  So absolutely you want a breaker
in the lines that feed the inverter.
For virtually anything you would normally need to run or charge in a Westy
you can find chargers or adapters that will run off of 12volts DC or small
appliances that run on 12v.  I run my laptop, a small LCD TV, phone charger,
shaver, lamp and flashlight battery chargers all with 12v adapters.  My 400
watt inverter gets very little use, only for chargers that I can't find a
12v adapter for.
As for the battery indicator light by the stove that will continue to show
the status of the starting battery unless you rewire the circuit that feeds
all the auxiliary items like radio and internal lights.