I'm sorry, I'm confused as to what you need.
Yes, you can approve that facetime calls go to all of your iDevices.
Anyone that knows your email address can send you a facetime request, just as they can send you an email.
You can block facetime calls on your mac, by Spotlight Search > FaceTime
Open the FaceTime.app, the click FaceTime Preferences from the top menu. Follow the menu dialog to block calls and setup any additional settings.