One of the problems for me about HN is the secretive nature of moderation.
Both those posts mention them already being involved in moderation before officially being declared moderators; you can do that too if you want! Just write email to hn@ycombinator.com if you see anything that you believe requires moderator intervention and they'll consider it.
I agree some aspects of moderation here are too opaque. While the mods will mention to users that they're about to be banned, or warn them about their behavior, this can take place enough after the fact that it's unlikely the comment will be read. Also, flags on your account, such as the loss of vouching or flagging privileges, or being slow-banned (as my account currently is,) aren't always apparent.
What might be useful is a message queue from moderators that appears on your account. This would not only make certain that users were aware of penalties to their account, but it would sequester discussion about it away from the primary threads.