don't think there is much, if any risk at all of someone not closing the main and energizing the lines- a typical 20 or 30amp generator would trip it's own breaker or stall with just the hot water heater or A/C on the homeowner's own panel, forcing them to shut off every breaker in the house (including the main) but the most critical lights & receptacles before bringing the generator online.
Maybe, but if the house is on a single transformer, and the primary is feed is open before the next transformer, then the primay will be energized by the generator without loading it down.
Don
