There're reoccuring squelchy noises when enemy units or your own units die during gameplay and when violence happens during the story, but these can be turned off in the settings via lowering the sfx meter.
Many of the main characters face/confront/defeat their abusers and/or the figures responsible for their trauma, but none of them stoop to their level or inflict the same pain and instead are moreso inspired to move on with their lives after facing them.
Kind of? a scene in the first chapter depicts a hellish alternate dimension (?) that the main character can pull open to bring the sinners back to life. the game is rife with hellish imagery and certain abnormalities could be considered demonic in nature.
It isn't on screen but it's heavily implied because of a prior canon event tw for mild description below and maybe spoilers
(lobotomy corporation branches locked down, burying the remaining employees alive, but this is an event that has existed for all of the current canon from the first game to limbus company)
While we have not yet encountered it in the story at the time of me posting this comment (after Canto IV, before Canto V), the official promotion video came with a list of content warnings that included Domestic Violence.
In Canto IV, a farm animal suffers an implied death during a black screen. During the final boss fight, dead animals can be seen lying in the background.
A character in Canto IV is routinely given drugs, and eventually stops taking them. Additional lore also suggests that N. Corp employees are drugged via food.
There is self harm through cutting in a scene in the Canto V dungeon, right after the first Abnormality fight. This same act is depicted in Heathcliff's 000 identity called "Pequod Harpooneer"
A cannibal restaurant exists in-lore, although it is only mentioned heavily in identities from the District 23 backstreets, a.k.a. the R.B. identities. Despite being event identities, these will be available in future gacha pools.
The only thing comparable to cops in my opinion are the K Corp Agents and possibly the security guards in Canto 2, and they're not portrayed in a positive light.
Shown graphically on screen and discussed in the cutscene right after the first abnormality fight in the Canto V dungeon. (Additionally, there is a Heathcliff identity whose pre-uptie art is based on this scene and shows similarly graphic self harm)
Canto 3 contains the main antagonists Kromer and the N Corp Inquisition discriminate against and brutally murder and torture people who use prosthetics. Several Sinner identities are also apart of this organisation and hold the same beliefs
Real-world religions are not discussed, but the N Corp. Inquisition dresses itself up as crusaders, including having scriptures, though only one optional uptie scene discusses that point.
In the first Intervallo of VI-5, the brother of the Intervallo's main villain (The Time Ripper) is hit by a car: his resulting death is what causes the main villain to Distort, and kicks off the events of the chapter.