in one of the endings, a side character helping the main character ends up dying and withholding information to help the MC. in Blood Mode, a character almost ends up sacrificing themselves.
I would say yes, it's implied. in Blood Mode, a specific character is tracked down and given a piece of food that eventually places a curse on them. in If Mode, a character says that they will 'take matters into their own hands' if the first mentioned person went down the wrong life path, so it's safe to assume that they are responsible for at least getting the other character spotted and gifted the food.
BLOOD MODE SPOILERS: it's revealed that Monika (the mother) had the Drevis curse of having to preserve human bodies in some sort of fashion. She manipulates Alfred (the father) into doing the murder and doll creation for her, so I think it's implied that she gaslit him along the way of getting him into that job.
in both Normal Mode and Blood Mode, a hanging body is shown. In Normal Mode, it's shown in the figure display room with the different caged rooms. in Blood Mode, the same body is shown during an exposition scene, it being seen with a kicked away chair underneath it.
while blood is shown on some of the character's portraits and shown in the form of pixelized hang prints and writing, there's not many scenes where actual gore is strongly portrayed.
So many, including the player in certain endings / if you mess up. Most deaths are offscreen but a couple aren't ex. Torture cutscene early on, an ally killed by dolls - most are just shown as ghosts or corpses though