I'm working on a website that has articles on which currently users can comment on, but has no FB interaction. I want to allow users to comment on articles using their FB and post the comments to their wall, but at the same time still allow users to comment anonymously, by simply entering a name and email as is the case now. I don't want to use the FB Social Plugin as really I want to be able to customize the comment section to suit my site, is this possible or can I only use the plugin? Preferably it would be done in AJAX.
The facebook plugin won't really allow users to comment anonymously. What you might be able to pull off though is taking their plugin apart and finding a way to load the content from facebook into an app on your server which can store the anonymous comments. This way facebook users who post will push their comments to facebook and anonymous users can post and you store their comments locally with timestamps etc so that you can push them into the facebook output correctly.
This is all theoretical of course, I've never bothered to take apart the facebook plugins and see how they work since they do what I've needed right out of the box so to speak. But they essentially just load content from a specific namespace/url on facebook, so in theory you should be able to figure out what that is/how it works fairly easily. I would check the iframe implementation as it's the most transparent way to see what they do and probably the easiest to "hack".