Displaying real name (from FB) vs username

Nope, not the best way, but for now, the only way. Now that 3.1 is out, one of our next big tasks is to revamp the JFBCLogin module to make it much more easy to style and give a couple of different default display styles (horizontal, vertical, compact, etc).

I've added the task of an option for username vs fullname, which should be easy to get into the updated version when we release it. In the meantime, I'd suggest making sure you used a template override for the changes you made to prevent them from being overwritten when you upgrade. For more information on template overrides, see the bottom section here:
www.sourcecoast.com/extensions/troublesh...ng-joomla-extensions

Thanks for the suggestion, and good luck!

Easy enough. We just released a new version 3.2 of JFBConnect tonight. The JFBCLogin module now has a setting for the greeting to use Username or Full Name. Let us know if you have any issues with the new version.