That "autodead" is usually for sites which require login (and no workaround), heavily spammy sites or from new users. None of those seems to be the case, may be worth emailing the HN admins. I've vouched in the meantime.
Likewise, but usually when the user only posts links, few comments. But the OP is a regular commenter and this only their second submission. Looks unusual to me.
If I had to guess, I'd say the submission title is not very good, not very descriptive. Not only that, but you submitted it with a title that is different from the title on the site. That's usually not a good idea.