Get user details

Is it possible to get user details (Email, Name...) through the API?  So the user enters his data through the Portal or can login with facebbok in the portal and I want to get this data.

You would be referring to the Query User Data in the Connect API.  Please, see the topic Query User Data in Cisco Connected Mobile Experiences REST API Guide, Release 10.2.

My understanding is that, via the CMX REST APIs, all of the data collected can be made available to any business application that needs it, allowing full integration in to the business processes of the customers.  I do not believe that personal user detail data is collected, such as email addresses, names, etc.  Please, see the topic Facebook Data Collection and other Facebook Wi-Fi discussions in Cisco Connected Mobile Experiences Configuration Guide, Release 10.2 - Cisco. 

I checked that through Connect API I can get some user details returned by facebook, like socialFacebookLocale, socialFacebookName, socialFacebookEmail, socialFacebookGender.

Is it possible to get more data like age, country...?

From an earlier presentation on CMX.

Facebook Page Insights

Demographics allows you to see several metrics including: 

• The percentage of people who like your Page for each age and gender bracket
• The countries, cities, and language of the people who like your Page You can compare the age and gender of the people with the same data for everyone on Facebook

See http://www.slideshare.net/EmergenceMedia/facebook-demographics-user-statistics-emergence-media

Also, see older documentation for MSE 8.0 which may still be relevant to the topic Cisco CMX Connect and Engage Configuration Guide for Visitor Connect, Release 8.0 - Cisco.