I see very highly rated negative reviews all the time. They even make a point to show you helpful critical reviews.

Is that true? Then why isn't everything 5 stars?

I don't think this is true -- it sounds completely antithetical to Amazon's values. Do you have something to back it up?

We sold some books on amazon as a publisher a few years ago (not just a third party but the actual listing owner) and Amazon happily removed any derogatory review we requested without hesitation.

To be fair, there is good reason for this but I am sure it is easily abused, but it is not like they checked the review, the action was near immediate when they got the request.