Next scenario. Fly ball to cf. Cf backs off and let's it hit the ground. Error or hit. Next scenario hard linedrive to SS hits off glove goes to OF.
Fly ball is a hit. Mental error or poor judgment is not a fielding error. ...
Line drive is more subjective, but I'd almost definitely rule that a hit. If the force of the ball took it into the outfield, that means it was not a routine catch. Lack of range or quick reaction time is irrelevant.