Well, a lot of what you describe as meta (e.g. "this page is unreadable") is explicitly against the site guidelines, and much of the rest is more-or-less implicitly against the guidelines (ie, HN is for discussions which gratify intellectual curiosity).

The right thing to do is to downvote it. If you can't downvote comments yet, well, they'll usually get downvoted by others soon enough. IMO, the nice thing about HN is that for all that it's imperfect, compared to most of the internet the community moderation (and official moderation) works very well!

There are also comments that are perhaps not exactly related to the story, but are adjacent enough to be on-topic or arise naturally from conversation. It's natural for conversations to move between topics, and many of these discussions are super interesting!