Hey LTN:
By default, if you have Google Chat check-marked, and GV configured on your OBi, you will be able to both make and receive calls. IF you instead want to receive inbound calls via a Callcentric DID (inbound number) which you have also added to your GV list of forwarding phones, then remove the check mark next to the Google Chat entry. You'll still be able to make outbound calls via OBi/XMPP/Chat, and inbound calls will ring via the forwarded CC DID number.
Hangouts works independently of Chat, and it does not know about nor care about the Chat forwarding entry on your GV settings page. Instead, inbound call ringing via Hangouts is individually enabled or disabled by checking a box in the Hangouts apps for Android, iOS or desktop/laptop web browsers. So: un-check Chat and check it in the Hangouts apps, and you should end up with your desired solution. Make sense?