Report that counts the number of Likes per article?

Not yet. Facebook doesn't have any built-in way to get a report of the number of likes throughout your site. We are working on a way to manage comments (something also lacking a good admin tool from Facebook), and in the process will be investigating similar functionality for Likes. We're hoping to get the first release of such an admin tool (included with JFBConnect) out within about the next month.

Sorry for the troubles, and hope you can wait a little bit for what you're looking for.

Facebook actually does a decent job of filtering obvious spam. They don't catch everything, but they have the ability to check comments across sites.. so if a user posts the same (or almost same) comment to 20 different sites, they have the ability to flag that. So, while very site-specific spam can get through, more generic stuff is usually eliminated before you even see it.

We're planning to use the callback for comments in one of our updates. Lots we can do with that. Again.. we're going to be focusing on comments and other social integration a bit over the next few releases. 3.2 will lay some good groundwork, but won't have all the features someone would want.. but hopefully will have something. Then, with feedback, we'll continue to refine things for 3.3, 3.4, etc.