Honestly, I really hate that shifters are considered as covering the lycanthropes archetype. They are a fine race and all, but it seems really underwhelming as an equal to the lycanthropes. There's no transformation, no savagery, no… lycanthropy to it, I guess. I mean, why play an elf/eladrin/drow when you've got half elf? I think there's a lot of potential there, mechanically and thematically, for a lycanthrope. (Which I figure fits into the whole creature of the night part of the shadow power source.)
As for the dhampyr/vampire thing, I can see why you would say that, but I also feel that that archetype would be better served as a theme as we, rather than a feat chain.
But its really up to you guys. :) Worse comes to worse, I'll just write it up on my own time and not put it in the book.