Trying to write comprehensive policies would end up interesting only the sorts of users who like policies, including the sort who will raise objections no matter what we do. The more policy we produce, the more objections and meta concerns they will raise, so to go down that road would be to perform a DoS attack on ourselves. It would suck limited resources away from things we can do to improve HN for the community as a whole, instead of just a vocal, litigious few. Since we're going to get criticized from this angle no matter what we do, we may as well take our lumps up front. If that sounds harsh, I'm sorry—it's mostly because policy-writing is the last thing my soul cares to do, and the bureaucratic parts of this job make me grumpy.
HN has always been curated, and that involves human judgment and interpretation—there's no way around that, no way to spell it out, and certainly no way to formalize it. As far as I can tell, the community is somewhere between fine-with-that and prefers-it-that-way. HN has always been a spirit-of-the-law, not a letter-of-the-law place, and we want it to stay so.
But we're fully open to answering questions. I spend hours each day doing that, in threads and by email. There's basically nothing people ask about HN that we don't answer. Before someone objects to "basically", I'm throwing that in because there are always corner cases (e.g., a question we can't answer because it would compromise some other user). You can't run a site this complicated without inconsistency. But the principles we practice are deeply about openness and satisfying curiosity. Even though we don't publish a full moderation log.
As for stories "jumping hundreds of spots", if you mean jumping up, that's the second-chance pool (described at https://news.ycombinator.com/item?id=11662380). If you mean jumping down, it's some combination of software penalties and/or user flags and/or moderation downweights. Most often it's user flags.