The Serious board is for religious, political, and other controversial subjects. Of course your opinion is allowed, and points of view that differ from the norm are expected; the rule you quoted is there to keep people from creating topics for the sole purpose of starting fights.

Not discussions or arguments. These are what a forum is about, so long as the arguments can stay civil and the members can refrain from attacking each other.

You might find this shocking, but people report threads in the Serious forum all the time. Just because someone reports it, doesn't mean it's going to get locked automatically.

So yes, you may report any thread you think is trolling or baiting. And yes, you may PM a mod if you are unsure about whether or not a topic would be trolling or baiting.