Sometimes I move posts to a better fitting sub forum.
The only posts that are removed occasionally are download/key issues once the problem has been resolved. And spam of course. the latter happens mostly automatically based on some heuristics WordPress (Akismet) runs on each post. Despite the need to solve a captcha there are is still a substantial amount of spam accounts created on a regular basis unfortunately.
If a post you made disappears e.g. after editing it (apparently sometimes considered posting the same content multiple times by the spam detection), or because it has (too many) links or some other formatting tags the spam detection dislikes, shoot me a mail. I can restore false positive spam posts for about a week or so before they get deleted for good.