I'd agree that hand-swinging pretty much any Rotax is not viable - they need a high speed to get going, have a gearbox which interferes somewhat, and also generally the prop blades are too darned sharp.
The 2-stroke Rotaxes mostly have an optional recoil starter fitted (a bit like a lawnmower's) which solves the problem.
On a 912? If the battery was flat I'd charge it or jump it, if the starter motor was poorly, I'd fix it. I'd not attempt a hand start.
However, I see no reason not to still treat the prop as live - it's basic common sense, which loses you nothing.
G