I always thought of it as Ira Steven Behr’s baby. RDM brought an interesting perspective. He said that there were diverse views behind the scenes—it wasn’t an atheistic, socialistic monolith that the Roddenberry worldview suggested. That could be seen in his episode where Jake and Nog learned about capitalism while trying to get a gift for Jake’s dad.
Never saw Caprica. Very much disliked BSG.
As for Andrew, I only knew him from Growing Pains. It was one of the few shows I watched growing up and he was a favorite. I don’t consider him selfish or a coward. It’s very hard to understand how dark a place he was in, but easy to imagine how it would seem there were few options open to him.
I think you've nailed an important aspect of RDM that very few people can or are willing to grasp. He did some outstanding work on DS-9, but it was under supervision by others who had a more coherent and disciplined vision of the subject.
However, when he was finally put in complete charge of a series his erratic, impulsive and narcissistic tendencies were no longer restrained and we got "stuff" like BSG and Caprica. Both series do show moments of inspired brilliance but it is more than negated by their extreme oscillations of incoherent, silly plotlines and contrived, forced emotional melodrama.