The Facebook Application process is definitely pretty confusing. They are making it simpler with time, but it's not necessarily 'easy'.
If you haven't already, please make sure you've read our
Facebook Open Graph Actions for Joomla
configuration guide. That should take you through the steps required.
The guide is for 'reading an aritcle'. You would want to update the action to 'review' (a non built-in Facebook action you'd need to create). You could either use an 'article' object, or something custom, like 'product' or 'listing-item'. Additionally, in the action, you'd want to change the trigger type from "Automatic" to "Manual". That should be all the changes you'd need.
As for JReviews, yes, right now, we only support posting an action on a 'review', not on a new listing. We're hoping to add actions for new listings soon, as well as actions on moderated reviews.
Hope that helps, but please feel free to ask any questions you may have.
Thanks,
Alex