In Oblivion we find out that one vampire and one mortal parent can produce a child . I think it safe to assume, though I could be wrong, that two vampires cannot reproduce. Even if they could there is the issue of the child not aging. But what do we know of the rest of their biology/anatomy? Since the disease can be cured and the subject restored to a seemingly normal life it must remain close to that of a living person, apart from the obvious changes. In Skyrim, for example, even as a vampire I can eat and drink but how far are game mechanics to be relied upon?

As a rule of thumb, not a whole lot. That said, Vampires are a...finicky subject. Given that there are quite a few different strains of it out there, how one type might function could be radically different from another, so on and so forth. The Grey Princes parent may be such an outlier that can't be taken as the be all for the others, and so on and so forth.

It's a Daedric Curse, with varieties spanning every province. No two Vampire Clans behave in the same manner. Vincente Valtieri, for example, had a hereto unknown Vampiric weakness to garlic. He contracted his Vampirism in Morrowind, so does that make it exclusive to one of the major Blood families of that province - or is it a mutation, brought on by a Breton having the Morrowind strain of Vampirism for over 300 years?