On the question of offering advice that’s contrary to what, say, your strata manager has given, there are ways of doing this that aren’t directly critical of the SM.
Say, for instance, your SM (in NSW) has told the committee that it can’t pass a by-law banning short-term rentals. Rather than saying the SM is wrong, you could post a comment that says something like “this is contrary to advice received from other sources” and you would then quote those sources and let the residents make up their own minds.
The more authoritative the source of the advice, the greater the chances of the SM reviewing their own position. But saying the SM is misinformed, biased, out of touch or, worst of all, is wrong AGAIN, strays perilously close to being malicious, which would undermine any defence against defamation.
Not every criticism needs to be an attack, but faulty advice should be challenged. However, “faulty” isn’t merely an opininion that disagrees, even with the majority. There are laws, regulations, tribunal decisions and court verdicts that are all readily available online, and which establish the basic facts of the matters under discussion.
Just be wary about the “bush lawyers” – online warriors who will cherry-pick a bits of laws and regulations that have nothing to do with each other, conflate them and then present that as a proven legal argument. Unless they can cite a documented precedent or are prepared to pay for a lawyer to run that idea through a court or a tribunal, their opinion has no more value than a chat at a barbie.