My experience of LW is that:
* the baseline interaction mode would be considered rude-but-not-insulting by most American subcultures, especially neurotypical ones
* the interaction mode invoked by "Crocker's rules" would be considered insulting by most American subcultures, especially neurotypical ones
* there's considerable heterogeneity in terms of what's considered unacceptably rude
* there's a tentative consensus that dealing with occasional unacceptable rudeness is preferable to the consequences of disallowing occasional unacceptable rudeness, and
* the community pushes back on perceived attempts to enforce politeness far more strongly than it pushes back on perceived rudeness.

Dunno if any of that answers your questions.

I would also say that nobody here has come even remotely close to "insult in every conceivable way" as an operating mode.