The overall rating reflects the current state of the app. It accounts for all app reviews but prioritizes the most recent ones.
My domain got banned by Facebook because this app
My domain is listed as spam on Facebook because this app
There is no reason why Facebook would ban you for using Blog Booster. We are a Facebook Authorised app, so any ban would be due to your content or activities outside of Blog Booster. Since you have been unable to provide further evidence regarding your ban it appears to confirm that to be the case. We have many companies using Blog Booster successfully and with a large number of blog posts, etc. without any issues.