Decisions and influences in Harry Potter

This all started because I was pondering Dumbledore, and "What was he thinking?"
I still don't know what he was thinking, but it's been fun making this huge diagram about various people's decisions in HP. I love GraphViz.

http://www.katspace.org/fandom/harry_potter/Decisions/

What do y'all think? I know I haven't covered everything, but hey, it's something.

ETA: I've now split the big diagram into four separate diagrams. Hopefully that makes it easier to follow.