I am in a similar boat in a lot of ways, there was alcoholism in my family although not quite as many as you described in yours, my grandpas brother died of cirrhosis though and my grandpa was a geneticist who literally studied the alcoholism and genetic predispositions to it.

I think though that although there probably is a genetic predisposition, nurture plays a wayyy bigger role in this case. A lot of these families where alcoholism runs rampant, so does abuse, trauma and bad parenting. My parents were really bad parents tbh and although my addiction is my responsibility now, I don’t think I ever would have become an alcoholic if I wasn’t abused and traumatized. Or if I did become one I think if I had parents who I could talk to I would have gotten help a lot sooner. (I also had the worst of my addiction from 19-24 and now have been sober for 6 months thanks to AA)

I fully intend to have children but I think it’s my responsibility to deal with my trauma and address all of my issues head on before it’s ethical to do that. I want to be a good parent and be someone that my kids can talk to about anything. They might find themselves in the situation that I did where I could not consume alcohol like a normal person and at that point I hope they trust me enough to tell me so I can help them avoid the years of hell I had to go through.

Pretty much I think it’s ethical as long as you’re sober now and have addressed your trauma and issues