Prop Turning.
As somebody who has experienced being struck by a propeller ( which shattered both bones in my arm) I cannot stress enough that ALL props are live. In my case, there was an intermittant live mag and I was careless pulling the prop through. Just by moving a prop by a few degrees may be enough to trip the impulse with disasterous results. Prop swinging aircraft that are normally started by starter motor are potentially lethal too - the prop is rarely in the correct position for hand swinging . Magnetos do not generate a spark when turned backwards and certain engines are regularly turned backwards to "blow out" an over rich mixture. I have heard that turning an engine with a vacum pump backwards is not recommended- likewise Rotax engines with a reduction gearbox should not be turned backwards either.