Vicky,
No, you can't use the JomSocial registration flow with JFBConnect. They're completely separate and don't work together. Since you can import much of the user's information from Facebook into JomSocial, a multi-step flow wouldn't work on most sites simply because a lot of the information would be hidden, leaving empty or near-empty pages to fill out.
JFBConnect also offers the automatic registration flow which automatically creates the Joomla account, bypassing all forms. Our goal is to make the registration process as quick as possible, and a multi-step registration process is the complete opposite of that flow.
As for the fields you can show, with JFBConnect, you can add whatever fields you want from JomSocial to the registration process. They simply need to be marked as "Registered" and "Required" in JomSocial. Then, in JFBConnect's Profile area, simply set the "Show non-mapped required fields during registration". The upcoming 4.2 release will have a lot more flexibility as well regarding which fields can be shown with the following options:
* Show All, Required, No JomSocial fields during registration
* Prefill fields that are imported (so that if you show the field, the pre-filled value from Facebook will be shown, and editable by the user)
* Option to hide fields that are being imported from Facebook, so the user can't edit them.
Hope that helps, but if you have other questions, just let us know!
Alex
Problem importing data/registration with JomSocial
