Regarding the name, I wasn't originally worried by it at all. As stated before, the D'Cerf family is more than just immediate; there are extended members as well, although they do not have right to the hereditary monarchy at all. Thus, I find it completely okay for one to have the D'Cerf surname for the character. I mean, Castor didn't mention he was going to play immediate family, which as I mentioned can only be played under special circumstances. Plus, who said Lord Bayard and the High Priestess Olwyn were even of direct descent of the original founders. If you want to get a spoiler, they aren't. :p I mean, as alluded to before, its perfectly possible for one not of original D'Cerf decent to gain rule to the throne, except I'm not about to explain how Olwyn and Bayard, in particular, got to their position just yet. I'll leave you in suspense.

Still, as the D'Cerf is a "clan name" as well as an actual family name (derived from the name of the original founders), it's also possible for those without any relation to the D'Cerf to have that surname as well, due to mere association. Some might take the name in solidarity or some other reason. Therefore, Atlas could very well be Atlas D'Cerf, but only if you want him too.