I apologize for the JS issues.. this seems to have been caused by a misconfiguration on my part (I did many years ago).. get_locale was returning 'en' and thus the FB API could not be found on the localized address it was looking at.
It seems to work fine now. I have just 1 remark: if you are not logged into FB and you login through the popup in WP, SFC does not - after logging in - show the publish buttons; it will still show the login button (there is no indication it was in fact successful). Instead you have to refresh the entire page for the publishing buttons to show.
Nicely done btw.. I especially like how all the functionality is behind a checkbox on the settings page rather then a separate plugin.