Good questions, but as a Dermatologist not on my *need to know list. I know why I needed Hep B fax: it had just become available and I was just about to start drawing blood as a medical student. I got 2 of the 3 doses in before receiving my first hepatitis patient. Soon not yet vaccinated friends were borrowing me for such tasks. But I don't think they were vaccinating newborns then. CDC site at a quick glance says babies can be infected at birth if mom has it, so I presume there's some data showing at least partial protection by vaccinating those kids at birth. But why to vaccinate the kids who mom tests negative for Hep B is a question for a different kind of Freeper Dr. And who's in charge of the plan details? I likely knew once, but don't recall. What I do recall is that whenever I've occasioned to read more deeply on vaccination recommendations in the past they've always had good reasons for what is included and when and have been supported by appropriate research. So I had faith in the recommendations then and haven't seen anything to question my faith since.
*Back when my Great-grandfather was practicing it might have been possible to know most everything of medical importance. In fact family lore reports his son-in-law the lawyer used him as a medical expert witness once (I think there was only 1 other doctor in the town then) and while establishing his credentials to the court my GGF claimed to be "an expert on the skin, and all parts within." Such expertise is alas no longer possible. I have to settle for being an expert 'outside' doctor and let others specialize on their parts of the insides.