These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Big Lipped Alligator Moment: The rather squick inducing memory Jessy's father had of a time when he had sex with her when she was 13. Please note, he is a minor character, one whose presence is pretty insignificant, making the moment even less plot relevant. Also, Nothing hitchhikes with an albino Fundamentalist who makes him perform oral sex on him, a part that seemed just thrown in to make Nothing's life seem even more pathetic.
Ho Yay: Zillah and Nothing are canon, as are Nothing and Christian. Steve and Ghost share one kiss. A later short story makes their relationship canon.
Idiot Plot: An Emo Kid who grew up with a fairly nice family, decides his life sucks and runs away to meet a group of people who don't even know he exists, gets picked up by a trio of vampires, one who happens to be his father, and to impress them kills his best friend. That is just the icing on the idiot cake if you think about it hard enough.
Gary Stu: Ghost has no discernible flaws (other than the fact that he let his best friend/crush get away with rape, but no one in universe is bothered by that), is described as being very pretty with white blond hair, translucent skin and big blue eyes (like a... ghost) is sweet and kind to everyone and even has Psychic Powers when it seems that no other character in the book, not even the vampires have them.
Moral Event Horizon: When Nothing is in the van and has the choice to participate in the murder of Laine, he participates at first out of self-preservation, but then because of his true nature, and it represents the beginning of his acceptance of a new life and new morality.
Older Than They Think: a lot of elements of this novel — sexy vampires, goths, New Orleans, and Ho Yay — have been so done to death that Lost Souls may look cliched. When it was published in 1992, those tropes were fresher than they are now.