The name and inheritance puzzle is a very interesting business, and one I've been looking forward to seeing addressed!
Personally as an American, I found the story of the creation of the Dukedom for the Percy family in the 18th century, and the Act of Parliament that passed for the Duchess's (though at the time she was merely a Baroness holding an Earldom) husband's name to be changed, a very interesting real historical example (the American part comes in as the 1st Duke of Northumberland, Henry Percy, was previously Henry Smithson, and his illegitimate son took the name after all this naming fuss and eventually became the founding donor of the Smithsonian).
I imagine that you'll find a way for everyone to be happy, and you certainly have a lot to play with in this realm!