A boy and a girl share a short kiss after the boy is found and saved from a bad fate, but they are young children and this is clearly intended as a relieved and concerned gesture, not a sensual act.

The villain's car crashes in a forest (he does not appear to be injured, however) and the trees (who are sapient) whack him away with their branches.

None.

Professor Coldheart (as well as the general idea of children running away or becoming lost and a strange adult luring or tricking them into danger) may frighten young children and somewhat disturb parents.