That sounds marvellous. Unfortunately, it can't work in reality. What actually happens is that some people believe they have a divine right to insult other people. When their victims complain, the abusers start gaslighting, saying that the people they victimise are being 'hypersensitive' and it is, after all, 'free speech' and the victims should grow up, be thicker skinned and stop crying like babies. When their victims respond by adopting the behaviour of the abusers and insulting them back - giving them a taste of their own medicine - the abusers suddenly decide they are not in favour of free speech after all and would rather everybody is polite.
In reality, free speech can't work in any complex social situation, such as a society or an online forum, because human nature works against it.
Free speech does work in social situations, complex or otherwise, when people are left to police their own speech. Those who step beyond the bounds of acceptability are dealt with by having their position ridiculed, shunned or ignored and excommunicated. That is how it has always worked before the advent of cancel culture and the "right" to not be offended.
To give an example; In 2009 the BNP were enjoying something of a surge in support, having taken a number of council seats and seemingly poised to take a parliamentary seat (Barking, fittingly) in the 2010 election.
Controversially this led to an invitation for Nick Griffin, the then BNP leader, onto "Question Time", a decision which led to protests and much hand wringing for "allowing" Griffin's hate speech, fascism etc.
I felt then, and still do, that if the BNP had enough support to justify inclusion, then this should be the only metric used. It is not for some anonymous arbiter to decide what we can say or hear. Who is this "Arbiter/Judge of allowed opinions? In a healthy society it is us who decide what is acceptable or the accepted norm by healthy debate; this may offend some but there is no other way.
Shutting down people like Griffin encourages the perception that others are scared of debating his "truths" and that he is being silenced. The best way to defeat "bad ideas" is with better ideas. It is notable that Griffin performed badly on QT and his ideas were shown to be hateful, ignorant, ill thought through rhetoric, not surprisingly. Shutting him down and giving in to the mob would probably have gained the BNP more votes; Allowing him to expose himself publicly with his batshit ideas allowed those who may be swayed, to see the BNP for what they really were.
Your examples are dealing with a separate issue. The argument used by you that people are for free speech until they are offended is over generalising. Which people? All of them? Were I to take offence at something you, or anybody else says, I don't expect anyone to censor you on my behalf. I can choose to respond or ignore.
The policing of debate between individuals or groups is a different issue to the policing of allowable discourse in the public commons by who knows who or what. They are not in the same ballpark, so I don't understand the relevance of abusers, victims, gas-lighters and cry babies to the issue at hand. It isn't about polite or impolite.