Ok…. on the Harry as a horcrux point: Yes, we all know he was not intended to be one, the book is clear enough on that. What people seem to be forgetting is that Voldy’s killing curse could not destroy the horcrux in Harry because it wasn’t there yet! Voldemort tried to kill Harry without realising the protection Lily had left him (‘the power the Dark Lord knows not’ — which Harry used again himself in DH), and it was only then, when his own curse rebounded, that part of his soul split (fragmented as it was already) and attached itself to Harry, thereby making him a Horcrux. Pretty sure that’s what Dumbledore explains to Harry in the Kings Cross dream scene, and it’s always made sense to me.