The PC's wife gets burned and ends up with a scarred face. The burning itself is not shown, but referred to several times and the scarred face is shown.
In one of the main game endings, the PC burns himself and the house down.
In one of the DLC endings, the PC accidentally burns herself and the house down.
If you choose not to use the crank in one of the rooms, miss finding it in the first place, or lose it when your wife kills you, you have to pull on a chain to open the next door. Audible screaming can be heard while the chains move, implying you pulling the chain is hurting someone.
There is one sequence where you have to fall down a pit, but it doesn't kill you. There is another, optional sequence to jump into a different pit, but I don't think that kills you either. I'll edit this later if I'm wrong.
There is a burn scar around the wife's eye, but we don't see the event.
An eye is shown with some of the optic nerve in the last chapter of the main game.
The wife/mother commits suicide. If you play the DLC, you play as the daughter exploring the house because your father passed (off-screen, not discussed in detail). You can find your mother's suicide weapon in the DLC as well and hear her portrait telling you she's going downstairs to take a bath (which is known to be where she kills herself)
No shower scene, but you see the bathtub both empty and full of water. This is also **SPOILERS** where your wife killed herself, though it's not shown.
There is projected body dysmorphia, where the PC sees his wife's scarred face as hideous and completely ruining her, when it's only a few spots.
His painting of her in the loop ending transforms into a significantly worse version and laughs at him.
**SPOILERS**
The wife of the PC (or the mother if you're playing the DLC) commits suicide. It's not shown, but her suicide note to her daughter is found, the bloody knife is found in both the main game and the DLC, and you hear her talking to her daughter in her final moments in the DLC.
One of the main game endings involves the PC burning himself alive with his house.
One of the DLC endings involves the PC accidentally committing suicide the same way.
Both the main game and the DLC have three endings. I consider one or two of them happy, but in the end nobody wins. Main - most common ending is getting stuck in a loop, painting the wife over and over again. Other two endings are the PC ignoring his abusive behavior and prospering as an artist or realizing what he's done to his family and burning himself down with his house. DLC - not forgiving your father and burning yourself and the house down by accident, forgiving your father and going home and treating your daughter the same way, and the secret ending of finding an untouched room your father set up for you to continue his legacy.