I don't think that Joss has any interest in a vampire/human detante - quite the opposite. And if he doesn't want to do that, hey, it's his story.

But Lordy, the argument that he couldn't/shouldn't do something like that because (horrors) it would raise ethical questions about what Slayers do, or because it would make poor Angel (and now poor Spike) look bad makes me want to bite tent stakes in half. I'd far rather that the series raise ethical questions, even if they have no easy answer, than tiptoe gingerly around them and then sweep them all under a soul rug.