Well I still have a feeling there aren't 4 Cruxes left. For Harry to find them all in would book would be going to quick. Dumby kept saying in HBP that he was guessing and that sometimes even he's wrong.

Is murdering a memory considered murder.....as in Tom Riddles diary? It had a soul or at least part of one. And Harry knowingly killed that crux ....now to think about it so did Dumby with Marvolo's ring.

Is knowingly destroying a Horacrux ..murder the part of soul?