The permissions are requested in order to provide the best possible user experience. Some of the permissions are for features not yet implemented in the current version. Rest assured that the data is never shared with anybody, ever! Furthermore, Smartr will never post without explicit user action, such as when the user posts to Facebook using the Smartr Inbox for Gmail sidebar.
You may manually remove permissions that have "remove" listed on the right of this page:
Note that you may experience limited Smartr functionality after doing this. Your Facebook access token may also expire and require you to add it again. If you wish to disable Facebook altogether you can do this from the Cloud account page:
We are considering a more granular opt-in/out options in future versions.