In the first situation, score a hit because (you say) even if the play were made cleanly the runner would have beat the play. Errors are only charged when the mistake creates or permits an advance that would not have otherwise occurred.
In the second situation, it's a judgment call. Contact with the ball is not required to score an error but you have to see something in particular to score an error when no contact occurs on a bad (spin-induced angular) hop. Not charging the ball is a sin but in this situation most likely not an error. But you'd have to see it to make the judgment call.