Somewhat, in later chapters, the main character asks god why he's allowing awful things to happen to him, and later he tells someone he no longer believes in god.
One character keeps snakes, having the nickname “snake” to go with. His snakes are always with him. They are deadly, but are not used to actually harm anyone
Ciel is drugged 4 times, 3 times to knock him out and once to kill him. While it failed to kill him, it did leave him in a state of uncontrollable fear and self-hatred for a couple of chapters
A character is shown to have had an attraction to the main character. He also had several young children work for him, and while he never says or does anything to them, it can be seen as pedophiliac in nature.
In chapter 135 Ciel gets raped by the cult members, not a lot is shown, but I would consider it NSFW and possibly triggering for some. It is also vaguely implied in chapter 19
There are multiple mannequins shown in someone's manor, from hanging from the rafters, being dismembered, to being put together but standing there in a rather unsettling way
In the early chapters, yes, as the other comment stated a trans character makes multiple sexual remarks to a male character, but she later grows away from it and acts normal.
Ciels ring, he wears it with an outfit, Elizabeth gives him instead of the ring lizzy(elizabeth) gave him, she decides to destroy it by throwing the ring on the floor(she didn't mean to break it/make ciel upset she didn't know how much it meant 2 him) he then raises his hand to hit her(Sebastian stops him) then he picks the ring up throws it out the window, later on Sebastian brings the ring back in one piece again!
In the Weston School Arc, Volumes 15-18, there f-slur is said many times, though in the context of the manga it NOT being used with the meaning of it being a homophobic slurs.
There is a system within the school where and underclassman will serve an upperclassman, doing things like washing their clothes/making them snacks, and the term used to describe it is the f-slur.
It is not connected to the slur itself, and the context of the word being used in the manga is not supposed to be homophobic, but it is still said several times.
In chapter 7, Ciels aunt disguises him as a girl so he won't be recognized at a party he's trying to investigate, as a young boy in the Victorian era he feels humiliated. Though in a later chapter, he does this again as his own plan and takes it with stride.
Grelle, a trans woman, is often referred to as he/him, though this is only in the English translation, in Japanese she is referred to with neutral pronouns
In the first couple of chapters she's in, Grell, a trans woman, is shown as hyper-sexual and a serial killer. Though as the series goes on, she slowly gains quite a lot of character development and mellows out.
Ran-Mao often wears short and very revealing outfits, she is shown to be objectified by multiple male characters, either in a gross way or a shocked/slightly terrified way due to it being the Victorian era
Yes, a character is shown to have a hatred for abortion due to her own trauma. Though abortion is neither shown as a bad nor a good thing in the series itself.