Add various social networking share buttons to your website, including; Facebook, Twitter, StumbleUpon and Reddit.
On the tutorial page; http://www.jpreece.com/wordpress/social-share-plugin-for-wordpress/
Yes, however it is only used on the administration pages to allow you to preview any changes made to the plugin.
Yes, you can use the Social Share Settings page (Admin > Settings > Social Share) to configure some basic settings.
You can also add custom CSS to control the layout. CSS classes are;