Jesus,
JFBConnect is very conservative on what it loads and how it does it. The Javascript that you mention looks like the below:
jfbc.login.logout_facebook = false;
jfbc.base = 'http://www.yourdomain.com/';
jfbc.return_url = 'LW==';
jfbc.login.scope = 'email,publish_actions';
jfbc.login.show_modal = '0';
jfbc.login.auto = '0';
That code is setting up some Javascript variables, which JFBConnect uses for things like logging in. However, those variables are not used *unless* the user is logging in. There is no extra processing required to set those variables, and it shouldn't be causing you any issues or slow-down on your site.
I hope that helps answer your question. If you really need to remove that block of code, we can help. There are features in our jfbconnect.js file that are used for the social sharing features (depending on how things are configured), so I wouldn't recommend unloading that file.
Thanks,
Alex