Can I use FaceTime video with an MacBook and email address only? I have a MacBook and set up FaceTime with an Apple ID, email only.

I can call from the MacBook FaceTime to another iPhone FaceTime user.

However, the iPhone FaceTime cannot make call the to MacBook's FaceTime, as the video icon is dimmed. 

Is email-only FaceTime a/c not good for receiving video calls?
You need to add your email account in your Macbook's FaceTime app and then get it verified from the verification email that you will receive.