You raise valid points with regards to risks of corporate takeover and abuse. If it is possible, then one day some faction will do it.
I am hesitant to completely get behind this idea, although I do like the principles behind it. What makes me hesitant is that it further confuses the already confusing Steemit platform. I immediately wonder if I'll end up being 'punished' by the system if I end up interacting with the same people too often. It seems like it's just another fine line to learn to tread on, which makes the learning curve potentially even steeper.
To solve this I would recommend having a fairly large 'grey' area in between good and bad influence, and keep some leniency in there. Focus the actual punishments on those who really abuse, but keep in mind that most n00bs make mistakes that they may end up getting punished for. An example is the cheetah bot or Steemcleaners, which frequently visit all kinds of posts which are 'maybe' abuse but most likely n00bs not knowing what the etiquette and way to go is. We need to be soft on the n00bs, and keep in mind that those with super low steem power don't really have any ability to game the system, and perhaps they shouldn't be punished as severely as whale accounts doing something abusive. Maybe the stricter rules start at a certain SP level, or something like it.