Bt he always wanted a child as you could hear in his voice in the ending. I don't think that Hilda could have ever had kids, must be somethign wrong with her fertitlity and it gave him joy that he has the opportunity to be a father.

I didn't understand your Vivi thing GuardianXIII especially about the shaking hands and crowd part or that other guy who said that Vivi's sons were confusing and unnecessary. I think that the ending is practially perfect. The only other thing I would've liked to have seen though is Vivi's grave at either the Black Mage Village or Alexandria castle since that's where four of his friends are currently staying.

Garnet probably layed him to rest at the village though.