These are some pretty nice propositions! What came to my mind while reading this is the idea of weighted reviews. Having ratings and reviews weighted by their authors usage behavior could be a nice addition to make the overall rating more representative, and reduce spam. Also some kind of algorithm based review list could be introduced, with the reviews labeled as e.g. “Long time user” etc. Other than that it could also consider both sides of the spectrum of reviews to show especially good and bad ones like amazon is doing it.