You seem to be misunderstanding the 1st amendment. It does not protect against speech that creates a "clear and present danger", such as yelling fire in a crowded theater (Schenck v. United States , 1919), but it most certainly does protect what you are now referring to, "hate speech".
You have posed two very different arguments. The first is a clear and present danger. The 1st does not protect against someone inciting violence specifically ("go murder <insert name or group of people>"), but it does protect someone who says "<insert name> doesn't deserve to be alive".
Your second argument is commonly called "hate speech" these days, and the 1st certainly does protect such things. As vile as something someone from the KKK might say is, it is protected. Why? Because hate speech is a subjective term, and there is no trustworthy authority that can define such things without human bias. For example, your example, it is socially acceptable for a black person to walk into a restaurant and say it. So, is it only hate speech when non-blacks say it? Okay, how <exactly> do we then define "black people"? What about people who are half black, quarter black, etc? This is a slippery slope with no definable borders. So the government is not entrusted with defining those borders, we simply rely on social norms to define what we consider acceptable.
The question I posed wasn't who to believe, it was who to trust to define what is misinformation. Let's use covid for example. Last year Fauci told us masks weren't necessary. The people arguing against freedom of speech claimed he was the authority on the subject. Then Fauci changed his tune and said masks are necessary, and admitted that he intentionally lied in order to avoid a mask shortage so doctors and nurses would still have access to them. Then he said 2 masks. Then he said one mask was enough. Where in that tangled web is the "truth"?
You are, again, misrepresenting my point. The point I made was that legally speaking, facebook is considered a social media platform so that it cannot be held liable for anything said on it's platform, but is simultaneously considered a publisher so as to legally allow it to police what is and is not said on it's platform. That is not how these laws are suppose to work. FB literally gets the best of both worlds, inexplicably. I will let you draw your own conclusions as to why our govt gives FB specifically the advantages of both types of platforms, when (for example) book publishers do not get both, and neither do other lesser social media platforms.
As for your point that if you don't like how FB polices content, go elsewhere... that was the same argument people made for not breaking up Bell telephone's monopoly back in the early 1980's. The problem with that argument is, legally speaking, what is defined as a monopoly. Bell (AT&T) had much less of a monopoly when the US govt decided it had too much power and broke it into separate systems (AT&T continued to provide long distance while regional Bell companies provided local phone service). But facebook is larger than Bell ever was, since it is literally a global monopoly of sorts. A global monopoly that, again, seems to get special legal privileges its potential up-and-coming competitors do not get. Factor into that how FB got together with the Apple Store, google, and a few other big tech companies to squash competitors such as tumblr and parler, and the case for a monopoly is clear. Zuckerberg has been in the news lately fighting against the anti-trust laws trying to be put in place to break up that monopoly for these reasons.