I would say that rules 4 and 5 should be lax within the bounds of common sense. For example, if your original topic has scrolled off of the first page, it might be good to start a new one, on subforums that don't bump topics to the top. I've also seen quite a few regulars change their "handle" (examples: Artelius and ChronoKitsune), or temporarily use joke handles (examples: Pete and Clippy), or post anonymously (example: ChronoKitsune). I've done it a few times. However, people who post anonymously shouldn't be too surprised if they get treated a little differently... Also, I don't think people should use anonymity as an excuse to be rude.
If a poster is anonymous, you don't have much "state" to work with. You don't know what the person's experience and capabilities are. Is he a beginner that you have to explain everything to, or is he an experienced programmer that you can give a more technical answer to? Sometimes, it is obvious from the post. But then, even within the same topic, you might not know how many "Anonymous"s you have. "Anon" and "Anonymous from Hungary" are a little more distinctive.
Personally, I like having something to identify someone by, if I am having a conversation with him. (Replying to a post is like having a conversation.) However, I recognize that some people might prefer various degrees of anonymity.
P.S. I am getting cached versions of modified pages. I am having to manually refresh.