Well, to start with, Suzanne was a fully formed human with her wishes and desires... Let me respectfully disagree with you.
Have you noticed how hard Barry was trying to be nice to people who were not close to him or did not know him well? I think the same applies to women. As long as women are not dependent on him and don't share their money with him, he "behaves". JMO. The moment the women trust him - it all changes, and he becomes sadistic. He is very angry at the world and has to take this anger on someone, and I expect the victim to be the person fully in his control. (With Suzanne, by weak I mean not her personality, after all,, she survived cancer, twice, but her situation).
Whether Barry would date a "strong" woman or not, I think, depends on a lot of other factors. Whether she looks well, is refined, has money. In other words, how much of a trophy she is. Suzanne was a big catch for Barry, and I suspect, things changed, first, when she had kids and he understood that she was not going anywhere, and finally, when she got ill.
P.S. I think a man like BM is at his worst when he uproots a woman and takes her away from her family, friends, culture, or religion. (Happened many times.. This is why the parents who come to visit their daughter married to a BM-lookalike are often in shock of the real situation.) In case of Suzanne, she was probably much safer in Indiana. JMO.