Don't worry, I've seen much, much harsher critiques of things on HN. I doubt you'll get banned. I'll have to keep in mind that the name YumHacker was so offensive to someone they were compelled to write an off topic rant about it, though.
As have we all. It makes me cringe thinking about it!
I doubt you'll get banned.
Your intuition is better than most; that comment has been punished enough. Things go much better when the community corrects things itself without moderators intervening. My goal is never to have to do anything. Edit: My long-term goal. :)