Replying in English, as site is only in English for now (je réponds en anglais comme ce site est en anglais):
- Forum component is not included in CB, you can use e.g. Kunena
www.kunena.org/
which integrates with CB.
(Utiliser p.ex. Kunena et activer intégrations CB et Kunena)
- To disable Joomla registration, turn it off in Joomla General configuration. Then make sure in CB general configuration, that registration is enabled independantly of Joomla config.
(Mettre enregistrements autorisés à non dans la config Joomla, et dans la config CB mettre à permis).
These settings are described in our free installation guide and in the complete CB documentation available to advanced members as well.
(Le forum joomla.fr a une section CB en français également:
forum.joomla.fr/forumdisplay.php?120-Gestion-des-utilisateurs-%281959-8126%29VSa
)