I think you are looking at this relationship all wrong. Your boyfriend is not damaged. Your boyfriend is not defined or explained by his experiences in this group. If you are going to have a healthy relationship with him, then you need to accept that he is no more damaged than you are.
Have you considered that maybe his point of view is valid? If you can't accept his point of view then you are going to continually have problems. You should forget about his past experiences and focus on your relationship. If you start labeling any of his actions you don't like as "dysfunctional" how are you ever going to have a good relationship?
We all come to relationships with different experiences and "baggage". Either partners learn to accept each other or we move on.
The question about what kind of behavior is typical is meaningless. Humans are all different, you can't categorize someone as an "ex-Family" member any more than you can categorize them as "ex-Catholic" or ex-anything.
A healthy relationship means respecting each other warts and all. Appreciate the things you like, either work through or learn to accept the things you don't like.
This is true of any relationship. Trying to pretend that your relationship is different than any other relationship because of something in your partners past is a very bad idea.