Since Hannibal has been added to Netflix, I have a few words of my own to share with incoming viewers.
Fanfic discourse in the Hannibal fandom is exhausting. Whatever argument you have for why the Hannibal fandom is "too dark," I need you to trust that we've already heard it, especially within the last few months, even though the show is a warning of its own. If you could survive the episode with the flesh angels, you can survive scrolling past someone's completely-optional-to-read fic on ao3 where Hannibal and Will's age gap is made intentionally larger, or a fic where Hannibal does something to Will that he didn't consent to (which is the basis of the entire first season, by the way). Learning to be okay with dark fanworks is part of being in a fandom based on dark IP, and if you can't do that, I'm going to suggest that you reassess which fandoms are/aren't for you.
If you don't like dark content, don't enter fandoms based on shows about dark content. If you can handle the heat of watching Hannibal, and you've decided that you want to engage with the fandom, you have to be comfortable with understanding that the fans --- who are mostly adults, by the way --- love the show because we appreciate Bryan Fuller's ability to make a beautiful story with macabre topics, and many of us are going to engage in discussion about macabre topics. At the end of the day, well-made transgressive art isn't going to have a sanitized fanbase. If you want a cleaner, tamer fanbase, find a source material that isn't about murder and cannibalism and manipulation and psychological torture and corruption and crossing boundaries. That's all you need to do.
As for the fact that most Hannibal fans are adults, I want you to know that the age of fans in a fanbase matters. Adults are going to be talking about adult things, since we are allowed to, and it's just annoying to get anon asks from kids saying things like "Why do you --- a fan of The Dark Themes Show --- enjoy writing about dark themes?" And, yes, it's usually clear when a high schooler sent it.
In a fandom like Hannibal, don't be surprised if people block you or refuse to follow back on the basis of age. We don't want to talk about dark topics --- especially dark sexual topics --- with people who aren't old enough to consent. It's a respect thing, as well as a protection thing (on both sides). If you want to engage with all (or even just most) aspects of a fandom as a teenager on Tumblr, find a fandom that's more populated by other teenagers. If you're okay with the fact that the Hannibal fandom is largely adult, you have to be okay with the fact that we discuss adult things. That's just how it works. Not every fandom is for everyone, and it's a matter of introspection to find out what you really want.
If you like the depth of Hannibal and Will's relationship, but you don't want a dark fandom, get into BBC Sherlock or House MD. If you just want a fun fandom that you can use to relax without challenging the way you think, get into the MCU or a sitcom or something. Stop walking into The Discomfort Room just to get mad when something makes you uncomfortable.
You were warned by the show itself.