Yes, he absolutely would if he said things here similar to the tweet of his that you quote.
On the subject of what happens to platforms that allow abusive speech, including ableism, see Free to speak. ECC Update - #13 by daira . For many of us that is an absolute red line: we will not participate in fora that allow abusive speech.
Yes we would, because I for one would kick up a huge fuss if we treated “celebrities” any differently wrt moderation policy.
Indeed you can’t. Deal with it. There are plenty of other ways to say that you disagree with what someone has said, or even that they persistently make flawed arguments.
Personally I find that it actually helps a lot to address the argument rather than the person. And tbh, it makes the very occasional cases where someone actually is just a raging asshole and you justifiably say so despite the risk of getting banned, all the more satisfying.