Yes, Vorenus and Pullo. There are some cute fics about them over at AO3 - Rome gets lots of Yuletide fics still, which makes me happy.

I also have a thing for Vorenus/Marc Antony, in a total terrible trainwreck kind of way.

Mary/Fanny subtext? Now this I have to see. No, it's not in the book (unless they've found one of Mary's lines that can have an interesting twist put on it...which would not surprise me. She's a very knowing girl.)

And I know what you mean about the BBC costume drama actors.