Mild. Large spiders try to attack two boys. Some of the spiders get run over by a car or killed by spells. One tries to bite one of the boys in a 'jump' scene, but gets repelled before it can wound him. That boy is shown to have arachnophobia, so he seems uneasy and anxious throughout the scene.
Dobby hits himself with Harry's desk lamp and a medicine bottle
Dobby's hands are heavily bandaged in one scene. He mentions that he had to iron them as a punishment.
A man falls off a window. No injuries, and he lives
A bludger chases a character in a Quidditch game and breaks his arm. Another character falls off his broom and lands awkwardly. The another character tries to fix the broken armed player with magic, but instead makes his bones disappear. He folds the floppy arm over in a gross way
Some magical dueling and mischief. Nothing worse than being knocked around
Dudley shoves into Harry's shoulder deliberately in one scene.
Some messages written in blood
Harry's adoptive family is abusive as usual, although it's tame compared to the first.
Harry faces off with a giant snake. A phoenix blinds the snake by scratching out its eyes. We see the empty sockets spurring blood. Harry stabs the snake through the roof of its mouth. Some blood is shown. He is also bitten by the snake and pulls a fang out of his arm. Wounds are shown, as well as dripping blood.