Concur on the miscasting of the movie, although I enjoyed the movie much more on a second viewing after I'd read the books. They really did a great job of shoe-horning in a LOT from the series. That said, both Aubrey and Maturin were totally miscast. I think Bettany might have been able to pull off a Maturin written closer to the original (cranky, dirty, secretive, obsessive), but Crowe was just... wrong. I'm not sure why: maybe he has too much interiority?

Hemsworth is not a bad idea, although I think he's much better-looking than Jack is.

I like your ideas for Sophie and Diana, although I would want to see them in action.

But who, WHO do we cast as Preserved Killick and Barrett Bonden?