The animatronics aren't haunted, they are controlled remotely... by the Phone Guy!
The Bite of '87? It might have been an accident, but the Phone Guy did it. He was getting used to the controls.
The Missing Children? The first two he lures away with the Freddy animatronic, he hides the bodies inside suits. Then he frames a guy with doctored footage and gets him arrested. It turns out it wasn't just two missing but 5 and that guy is convicted.
His nightly recordings are all staged, he wants to play with the emotions of his victim night watchmen.
He disabled the camera for the kitchen because that is his base of operation during the night. From there he is able to monitor what you monitor and work towards capturing you by disabling your camera for a while so he can move an animatronic.