Migrate JomSocial Facebook Connect to JFBConnect

Julio,
I'll answer as best I can, but if you have other questions, just let us know:
1) Yes, when the user registers through JFBConnect, they will also have a Joomla username and password that they can login with as well. JFBConnect can be configured to automatically create the username and password for the user (like on this site, where your name is julsen and your password should have been emailed to you) or an actual registration flow where the user can set their username, password, and you can actually show extra JomSocial fields to the user in case you can't import them. You can try the registration flow on our demo site below:
demo.sourcecoast.com/
In the admin area, under configuration, you can change the "Registration Flow" setting to see both options as well.
2) Yes, JFBConnect has a one-click migration that will import any previous connections from JomSocial into Joomla so that your users won't notice the difference.
3) Yup. We've done a lot of testing with the Canvas and Page Tab areas. In both cases, you shouldn't have a problem registering new users in that section. You can even set a different template that only works in the Canvas or Page Tab views so you can have different looks for your 'live' site vs when it's displayed on Facebook. Again, some links to the demo site:
Canvas Config information: demo.sourcecoast.com/index.php?option=co...cle&id=13&Itemid=188
Canvas URL for demo site: apps.facebook.com/joomla-to-facebook/

Finally, we have a 30-day money back guarantee. If you can't get things going how you want, no worries!

Hope that all helps, and good luck,
Alex