Swythyv, your thoughts on polyjuice are just plain scary! There are enough people running around with double agendas/double natures/ disguises without adding more! Were you the person who came up with Draco as Tonks/Draco as Madame Pince, etc?

Good gracious, no! Just watching them from a safe distance. As you say, there's enough to make my brains go round all ready. ;D

a sign that he was working for vengeance on the death eaters from a very early age.
I strongly concur - I think Snape was up close and personal with real life war/tragedy when the Marauders were still sniggering over Zonkos tricks in Hogwarts halls.