To begin with: I agree with much of what has been said in this thread. So if I don't comment on your post, it probably means I agree.
It's not that easy. For example, saying "Open carrying a gun is always legal, because of the 2A" is just plain wrong. It is not a valid opinion. Saying that isn't a crime, but it is the kind of thing that should not be written here (nor anywhere else) without being corrected. And if nobody corrects it, or if the corrections are ineffective, it is also the kind of content that a moderator should remove, because it is extremely bad advice, which (if followed) would get someone into jail.
Now we have to distinguish from a few different cases. Saying "Open carrying a gun should always be legal, because of the 2A" is a statement of opinion. And whether that statement is a good policy or not is something we can debate, but as long as it clear that it is a wish, not a statement of fact, there is no need to moderate it. The change from "is" to "should be" is vital in this distinction.
Contrariwise, saying "Open carrying a gun is always legal, because of the 2A, and anyone who says otherwise is a

t libtard who needs to be ignored or worse" is not only wrong, but also insulting, and an attempt to immunize the wrong statement against criticism and correction. That kind of writing needs to be moderated away immediately. And anyone who repeatedly writes things like this and is incapable of learning the difference between right and wrong, between wish and reality, between open discourse and factionalism, should be banned, because they are just going to disrupt the forum.
So I disagree: factuality of an opinion does have to enter moderation
Sadly, I think the opposite will happen. Unlike most computer-based things, the scaling here is likely to be hyper linear. The more the forum grows, the more it will attract wackos from all ends of the spectrum (the spectrum is multi-dimensional and has more than 2 ends). I fear the moderation effort won't shrink, not even in relation to the number of posts.
Are you saying that moderators have killed the r/CAguns subreddit? I don't see that; there are lots of people there asking questions and getting answered. And it seems that extremist opinions (all guns are evil, or all guns for everyone all the time) and political grandstanding are pretty well moderated away there.
Finally, I'll add that I just agree with this.