The SCLogin module doesn't have any way to automatically pop itself up. The 'show unauthorized links' setting is a Joomla setting and it will automatically take you to Joomla's login functionality. That's just how it's built and there's no way to hook into or override that method.
In general, we recommend making sure your standard Joomla login area 'looks' good as there are many components and Joomla features that will automatically redirect users there. JFBConnect does have a setting to add the social login buttons to that login component view as well.
I hope that helps explain, and sorry for the very delayed response.