Hi,
How to protect the kids. Good questions! I didn't do a very good job of it. My xah is in another state now so I don't have to worry about it but it is a valid question.
Regarding your 7yo not saying anything. My kids were a little older when we separated (8yo and 10yo for the big boys) and when I had them in counseling they didn't express anything either - which at that point I knew it couldn't be right. There counselor explained something about growing up in a dysfunctional home - especially one with alcoholism. There are three unwritten rules in families living with active alcoholism.
Don't talk, don't trust, don't feel. I sure cried that night because my boys learned those lessons well. To well. They learned them because they lived it and because it was modeled. There was no trust in our house. There was very little talking because we were busy ignoring the elephant and trying to survive. Rage was consuming us from the inside out so we didn't feel anything because to open the feelings door even a crack - opened the gaits to hell as far as I was concerned. Resentment and anger would swallow me up and if that didn't happen something very bad might happen to me if I let out the secrets of my true feelings. I would somehow get hurt. My kids have two parents that grew up with and lived those rules, raised by parents that lived those rules. Despite the fact that I want it to be different, I have to learn how to make it different because I really have no idea how to live in a family that talks, trusts, and feels.
There is a price to be paid by living in a dysfunctional family, even if it isn't one of violence and abuse.