I think all topics are ok, as long as you are willing to learn about it to present it properly. Instead of just for shock.
For example, if you want to do religion that you are unfamiliar with, learn about it first.
Or, even on a taboo topic, say, incest-necrophilia(?), if presented in the right universe with the right voice where the characters have purpose and meaning, it can be done. Incest in game of thrones for example, is handled as a plot point and not just for shock. Necrophilia is in some classic short gothic stories to symbolize love beyond death.
I am not sure how I feel about pedophilia, but I guess there are some stories that portray it in a way that is "I don't want to love them, but I do and I need help."
Anyways, agreeing with others here, in that it is ok to touch topics, but do it in a way that doesn't spread hurtful ideology I guess.