Re: Redundant heating/cooking/power sources
in my expierence, the most reliable items are simple. Adding a lot of complexity to the mix often equates to less reliablilty. Steam is an awesome source of power...and by awesome i mean awe inspiring! There is a crazy amount of power available there....but also deserves a ton of respect. Boiler explosions are bad. steam boilers tend to be heavy and probably not the best option for a skoolie....but you can do anything you put your mind to.
Why not have separate redundant heating sources? A woodstove puts out a ton of heat and should have no trouble heating a small space like a bus. Electric space heaters are really cheap to buy and come in several varieties. a gas furnace is perhaps the most convenient heat source depending on your gas and electric supply.
a liquid cooled diesel engine seems like a good option to add some redundancy. you can use the engine to make electricity, and use the coolant to heat the bus....and it can run on hho, diesel, kerosene, jet fuel, biodiesel, or wvo....so there are lots of options.
Quis custodiet ipsos custodes (who will watch the watchmen?)