I'm upvoting because despite the personal drama on the site, the question of what constitutes acceptable offense is an important question, particularly in an era of cancel culture where anyone who is offended believes they have the right to disenfranchise and censor others. Offense is a poor measure of incivility, because inevitably, bullies figure out that they can either feign being offended or can be permitted to be offended at anything feigning victim-hood. Those gassed at Dachau were victims. Those who must tolerate that others believe Dachau was staged are not.
You cite:
This answer is just copying <organization I don't agree with> Propaganda. If anyone wants that, they know where to find that website.
and
This user is posting lies in his answer. Such-and-such claim is yet another lie. What ideological commitment leads him to lie?
Now, the question of defamation and offense boil down to, is it true? In other words, if you are copy and pasting lies and propaganda, then offense is irrelevant and there is a lack of defamation. Personally, wading through creationist and atheist arguments that are simply a steady of slough of invective is boring at this point, and I encourage everyone to strive for a pluralist and quietest approach to discourse. But if one's tactics are simply rhetorical with a healthy dose of deprivation of reason, then one should be called out for it, offensive or not.
This site has its fair share of extremely intelligent users, and its fair share of argumentative types who emphasize argument-as-conflict rather than argument-as-shared-exploration. Ultimately, explicit insults are off the table, and snarky inferences should demonstrates some sophisticated semantic acuity. Free thinkers and philosophers of all stripes tend to value freedom of speech, so as long as the offense isn't from explicit attacks and crude language, it tends to be allowed, because the freedom of speech is more important than the freedom from offense.
That being said, I'm not weighing in on your particular experiences, but want to stake out the idea that we regularly get religious folk who get offended when they are called out for their (often unaware) use of rhetorical tactics that lack dialectic merit. I myself own no fewer than three books on informal fallacies, and I come here expecting some measure of sophistication in reasoning and argumentation, and as far as I can tell, as a free and open site, there is no better place than Philosophy SE to find thinkers of all stripes.
So, if you have been maligned unfairly, don't take it so personally. There are trolls under every bridge. But if have been mindlessly promoting views without critical thinking, then it's fair for members of the community to suggest that your critical thinking skills are wanting. I've found the latter group tends to have difficulty dealing with an criticism because they often emerge from thought communities that are themselves intolerant. Jesus was certainly a victim. Giordano Bruno certainly suffered. I think there's a general reservation of critical thinkers to attribute great suffering to those subjected to snippy language on the anonymous Internet.
That being said, the moderators here are volunteers, rather disinterested in anything other than facilitating good Q&A with the sometimes feisty sidebar, and for the most part, are fair. They are often themselves subjected to criticisms, direct or otherwise (I am a prior offender of the latter method), and do an excellent job of helping to herd the proud collection of cats that gather here gasping for genuine intellectual discourse. As such, if you repeatedly flag posts and are ignored, I'd take that as a sign that you are at least part of the problem.
Other than that, please continue to contribute! A community has to welcome people to its fold, help them integrate into the norms, and encourage participation. Moderator Phil is despite his claims of being a differential engine of reason on the spectrum, actually a patient and tolerant guy with a subtle sense of humor, and other contributors routinely provide their expertise free of charge. If you come across some (fellow?) combative types, find an equilibrium, and respect the difference of opinion, even if that means you must be the bigger man (metaphorically and without disregard to non-men, whatever that means these days).