I think the discussion shouldn't be about what should be censorship but rather who decides it. So if you put, lets say illegal pornography, on your page, then there is a law that forbids it. Especially in a good system the person who posted it gets prosecuted. On the other hand if companies act like judge and low, it can lead to bad things I think.
Inciting violence and overthrowing a government is already as illegal as child pornography is. Would you rather have all child pornography kept online up until a judge has declared that person guilty?
No, that's not right. See Brandenburg v. Ohio - incitement is explicitly not legal, per the Supreme Court. The classic qualifying line is "imminent lawless action".
The Supreme Court found that Brandenburg's 1A rights were violated. The "imminent lawless action" doctrine was protecting his ability to advocate for violence.