Wow, this is amazing analysis! The first graph looks great - it looks like powerful users are using a lot of their votes to support newer and less established users. But the second one, showing the differential in voting power weight, is interesting...

Perhaps the most established users get more 100% upvotes because they are the ones who create the most in-depth content? There are a lot of planktons and minnows that, frankly, make sub-par content. They are trying, and I support them with smaller upvotes, but I can only do so much for some of those posts.

On the other hand it could be a sign of nepotism. Hard for me to say.