There are moments where characters will lie/omit information for their own gain, but it is more of an overt form of manipulation/lying instead of gaslighting proper.
There are moments when the player's sanity/sense of reality may be called into question, but it is often out of sincere concern for the player's physical/mental state or genuine disbelief in some of the more fantastical elements involved.
One character struggles heavily with alcohol dependency. This is an important aspect of his character, and is mentioned frequently when he appears. Empty bottles can be seen strewn about his home.
There is a character who is addicted to morphine. This is referenced not only when talking to or about her, but also in item descriptions for morphine and tourniquets.
You play as a doctor, so organs and such are discussed often. There are art assets of organs, but they are still images and not drawn to be disturbing. Similarly, there are a few "wet" sound effects that take place during surgeries. There is also a late game-sequence [SPOILERS, DESCRIBED BELOW]. However, I wouldn't describe any of it as excessive.
[SPOILERS: where you walk inside the guts of a large creature and see its heart, though this sequence is not bloody or particularly graphic.]
Not really. However, there is much discussion of the sick and the dead, and you see non-graphic images of organs and hear 'wet' noises associated with them.
It is possible for any named child to die, corpses of children are also seen outside the theatre, and there is a dream sequence which shows several hanged children.
Occasionally, a character will chase down the player to deliver a message, and there's no real warning for it before you're forced into a dialogue scene. It's not accompanied by any loud sound or flashing, but can be startling.
In one ending, a character talks about taking actions that he knows will lead to his death. In another part of the game, he also mentions killing himself when the Inquisitor arrives in town
Frequently. The fourth wall is played with from the beginning of the story until the end (especially whenever the player dies, in dreams, and on the last day.)
Starting on Day 3, there’s side quests involving babies in infected houses. The player will sometimes hear baby cries while in infected districts, and if they break into the house, they can find a baby and take it to the town hall. Taking action on it and seeing the actual baby is completely avoidable, but the cries will still be there, and the woman in the town hall will explain about it on Day 3.
One of the Herb Bride models is completely topless and the rest of her clothing is rather negligible, making her practically nude. Other Herb Brides are more covered, but still scantily clad. Eva Yan's outfit mimicking the Herb Brides' is also very revealing.