RE: Master power switch
hi there from Toledo
at the Flying Tigers field we require the use of a removable shunt type circuit on epower planes. There is just no question of whether the plane is alive, if you have the shunt connector in your pocket. It is the last thing you plug in before flying and the first thing you remove after landing.
Some fellows use Dean's ultra connectors for their shunt connector others use Anderson power poles, both work great and totally safe.
A switch with the necessary current handling capacity is usually too large and heavy to be really practical. And then, which position is off or on? Did you bump it accidentally? Make or buy a safety shunt circuit, you won't regret it.
ciao -rjf