CB Connect registration configuration

The usertype column in Joomla is completely unused unless you're on Joomla 1.0 or 1.5. If you're wanting to set a field value when the user registers with CB Connect you'll need to act on the after registration trigger then check if the social site ID field (e.g. [fb_userid] Not Empty) has been populated then change your fields value using a Field action.

Following on post No. # 249260, it is possible with some settings or some component CB after you have registered with a social on the confirmation screen "Accept terms and conditions" (see screenshot_1) display the field "cb_usertype" as the example in the screenshot_2 (where warns that e-mail already exists).
Thanks.

No, not without modifying CB Connect and adding that. Next release of CB Connect will allow you to pre-fill the registration form with their social profile information (it'll still be possible to skip this though), which should cover your usage as you'd use the pre-fill feature so most of their information will be completed for them.

In CB 2.0.4 and CB Connect 6.0.4 by registering with Facebook and Google account in the field e-mail the e-mail address is automatically loaded (see screenshot "With E-Mail")
with Twiter and LinkedIn this does not happen (see screenshot "Without E-Mail").
Is normal or it can be set so that they are displayed?
Thank You.

Yes, that's normal. Twitter and LinkedIn API does not give an email address. Profile data is not guaranteed. Some information the social sites will not provide.