The way my system is setup I plug the shore power into the inverter BUT first I turn of the breaker at the Converter that controls charging the batteries. I also throw the breaker for the AC just so it don't come on automatically. I have to unplug my refrigerator to force it to gas otherwise it chooses electric for you if it's plugged into 110. My Hot water heater is propane only so not part of the loop.
Good to know about cleansing the panels I really don't want to have to go up on the roof all the time to keep them clean.