Sort of. Lefty was designed especially to contain Puppet so that she couldn't escape. And while we're never shown in person, it's implied that Puppet was inside Lefty the entire time.
It's more of a murder-suicide, but Henry sets the pizzaria on fire with himself, Michael, William and all the possessed animatronics in it and makes no attempt to get out.
Possibly; one minigame shows dead animals of indeterminate species, though it's all in 8-bit. Also, Candy Cadet tells a story in which several kittens are eaten by a snake.
One of the minigames has Helpy trying to jump into a ballpit. If he misses, a bone-cracking sound can be heard and Helpy will lay motionless on the ground. It's not permanent and he will be back alive immediately after.
No, but it's possible to unlock an ending that heavily implies the player is sent to an asylum, and the avatar of the player is shown in a strait-jacket.
No, but take care you don't have one yourself. Also, if you don't tend to your vents enough, a sound clip of heavy breathing plays, and the screen darkens.
Not really. But Charlie is a female ghost inside a male animatronic's body. Those who know refer to her with female pronouns, but those who don't use male ones.
Midnight Motorist, the video game, has a secret cutscene that implies someone is driving drunk, often driving in the wrong direction in heavy traffic. Also, another minigame plays audio of a car horn honking, and an animal is implied to have been hit by a car.