I'll be completely honest, I didn't know that we auto-logged the user into the back-end in the previous version. It was never an intentional functionality, but I can imagine how it worked.
We've tossed about the idea of allowing JFBConnect to work in the admin area (with a login button on the admin login page, if so desired), but have shied away from it. This is mainly for security reasons. Although we don't know of any security problems it would cause, we try to be safer than sorry-ier
The comments/likes per category is coming. We really focused on 3.1 recently, but now that it's out and seems relatively bug free (as always hoped for), we're now focus on the next set of highly requested items, of which this is definitely one.
We'll look into the auto-login for admin area more, and let you know what we come up with. It would likely be a setting to allow it in the admin area first, just so people can disable it if they really don't want that functionality.
Thanks!