Maybe I'm missing something but this is pretty terrible card. Just take unexpected courage which always gives you +2 so you can at least succeed instead of failing. And if you happen to pass, you get +2 anyways.
The only benefit of daring maneuver is like Lucky!, you can play it after the fact to get guaranteed value. Unexpected courage gets wasted if you draw the auto fail token or you fail because your skill even with unexpected courage was just too low (should be somewhat rare).