Never turn power off, even at home, plugged in 24x7x365. However, I fill my fresh water tank, and never hook up directly to the water spigot any more and run water via my on-board pump. Just as a precaution, I do flip the water pump switch off if we're going to be gone for any length of time. (if I remember to do it). Never turn water heater off (gas or electric or both) and never turn the refrigerator off either.
Even when in transit, I'll turn the water pump off as we always carry a little bit of water in the fresh water tank for toilet use on the road. Refrigerator is never turned off. Of course, on the road, the water heater is turned off.