My husband has nightmares if he sees violence. He closed his eyes during the scourging, as he does for all violence in movies for a long time.
Yes, I think young children could have nightmares especially very young children who naturally have nightmares about maiming as they transition to different states of maturity. However, older children are different from each other and depending on the child, some could see this movie and be fine, where others would be upset, like many children were upset seeing the WTC collapse.
Child abuse? That's over the top, but Janette is European and they have more liberal views about corporal punishment and the like, and would be more inclined to call many things child abuse that the average American wouldn't.