Striving to behave well is pretty much the best guideline, and if you incur some punishment unjustly or accidently, then contact the HN moderators.
HN is not a "whatever isn't explicitly prohibited is allowed" system. Instead it flows from general principles, and one of those principles appears to be that if you're caught abusing the system, there might be negative consequences because abusing the system is detrimental to its integrity and probably creates more work for somebody.
Good referees make the calls that need to be made at this time, in this game, with these players. They have discretion. Compare that to basketball where all fouls must be called even when calling the foul clearly rewards the team committing the foul and gaining that reward was the explicit reason for fouling.
The reason futbol can be officiated differently from basketball is because futbol has Laws and basketball has rules. The futbol referee doesn't judge events solely by the book, but also by their effect on the Spirit of the Game.
The duplicate post heuristic exists to prevent problems and maintain the general enjoyment of HN. It's not there to encourage lawyering up and arguing a case, because that's nothing but a headache.
If this is seriously likely to affect you, act on the side of caution. Act as if the rules were explicit and restrictive and the punishments severe. In other words don't try to get away with something, and if you do, don't complain if something unpleasant results.
As Thomas Hobbes theorized, the sovereign's sole responsibility is to do whatever is necessary to keep the peace and we cede some of our autonomy for the sake of that peace. It ain't a democracy.
At least in futball, you know who the refs are (hi dang!), what the rules are, and you know whether you've been red-flagged. On HN, the mods are new, the rules are unknown, and the default behavior seems to be not to tell anyone when they've been penalized.
You seem to be talking about a complete list of rules. It's doubtful that we'll try to formalize HN in this manner. For one, I don't think it's possible; but if it were, I doubt it would work, and if it did, it would probably do more harm than good.
I get that that's frustrating to anyone who would prefer a precise spec, but don't forget that there is at least some compensation for the lack of an exhaustive rule book: you can get answers to questions by asking us. Please send questions to firstname.lastname@example.org.
This sounds reasonable enough. But how will I know when to ask a question? It's not just hellbans; it's my understanding that there is no notification when one's account is penalized for some technicality (e.g. deleting a post before posting a dupe).