Thank you for your suggestions.
By "eliminating the repetition" I understand you mean of the font tags. I assume the <p> tags are still done manually. eBooks support a limited number of tags so this simplifies CSS. Some formating is done automatically by the reading device.
So how is the linked code otherwise, as a whole? Any "bad practice" issues I need to ditch?
Should it be XHTML compliant? Are header tags (h1, etc) standard now? I never could fathom the rationales for the many ways to specify font size: px, pt. em, +2, etc.
Coding is actually fun, once you get started. But I can't figure out exactly why.