I agree with most of your points, I just don’t think any of them cross the threshold for what should be considered free speech. I also don’t think the default assumption should be antisemitism or holocaust denial or whatever.
The Nazis were obviously worse, but the vast majority of people saying they are the same are just being hyperbolic or at worst ignorant. The vast majority of people saying the state of Israel should be abolished (at least on western social media) do not mean “the Jews dont deserve a home” or “it should be abolished through the killing of all Israelis”. And yeah there’s no short version for the Zionism issue on this end either because it’s a word that can mean anything to different people.
Usually much easier if one person takes the lead yes. If you’re lucky it is obvious from the start who is better qualified or even interested in doing so.