Hi,
I'v been playing with FB integration modules for the last 16 months, and I discovered this module only couple of weeks ago - there is a really big mess with all the FB related different modules on drupal.org.
This module is by far the cleanest, simplest, efficient, and robust module that integrates FB login to drupal sites wich is what 90% of drupal based site admins are looking for their sites.
After saying that, I think that adding a tick box to the admin UI that will enable to add the connect button to the user login/register forms pages is really needed.
There is no need to translate it or to position it Just enable to insert it somewhere, it will help to convert more new users to the site as sometimes they are reaching to these login pages when trying to comment or to do any other authenticated-user related action.
It will not conflict with other modules. and if it might a warning that it might will do just like the warning for the pop-up login window on the module admin UI.
To make the long story short, please consider to add it. I don't think this is a theme related issue, it should be available as a built in functionality. it will not harm nodule simplicity - just enable to add it on the register/login form pages only, i think this is a very needed improvement for this module.
Well done job quicksketch, this is an awesome module! a perfect KISS!
BR
Itzhak