Regarding #1, in some motorhomes, such as mine, a Fleetwood Tioga, even if I turn the battery disconnect switch to off, when I hook up to shore power, it automatically turns on the switch. so I don't have to bother turning it on. This is most likely to enable the house batteries to maintain a charge. Try it. Once you are hooked up to shore power, attempt to click on the disconnect switch, you will find that it is already on and you also cannot turn it off. But even with the switch off, and away from shore power, you most likely have a carbon monoxide detector that keeps taking power from the batteries, slowing discharging them.
