PG wrote about this here: <a href="https://news.ycombinator.com/item?id=6813226" rel="nofollow">https://news.ycombinator.com/item?id=6813226</a>.
No one here is likely to hold a grudge. I see you got hammered on one thread, but once you figure out what specific things to avoid then people will treat you appropriately.<p>I have had a few comments downvoted. Some of them a lot, but I learned that sarcasm doesn't translate well in text. Complaints about downvotes get downvoted every time, usually even by people who didn't mind the first comment.<p>If you are worried about your karma level then try to post interesting stories you find elsewhere. A comment will never get more than a few upvotes, but you can get hundreds from posting a story.
I don't think you can. You can scrub your profile of identifiable information, change your password to something random and then forget it, though.