Many things scare me with it.
•The thought of a structural failure or a main spar failure is probably the scariest one.
•Uneven flap extraction and a snap roll at low level. This is why I check flap connectors even more rigorously than ailerons.
•Descent through IMC layer in hilly terrain with an engine failure.
•Single engine over long water stretches.
•Single engine fire.
•Blade separation in a twin.
But as usual, one manages those fears.