My parents stayed together far longer than they should have (I'd argue that they never should have married just because my mother was pregnant) in large part because of the wider community that had the attitude that keeping the family together was all important, but did very little beyond that platitude. With what you've written OP, I'm wondering what wider supports you have available to maintain this ideal?
They didn't shout much, though a few times are very memorable. They were just very distant - my mother slept on the couch most of the time when my father was home, one would hide away in the bedroom while the other was with us, and they kinda gave up certain areas of our lives to the other -- my mother always did X, my father Y.
We looked picture perfect, but they were so miserable, there was always that edge and I'd wish that they would separate from about 9 or so. I could smile and perform the role but I never felt comfortable. Within a few years, and a few 'fresh starts', I was exposed to far, far worse than just my parents being separated - my mother was taking 'mother's little helpers' among other drugs and the whole 'stay because of the kids' mantra meant she pretty much blamed us, particularly me as the second born (I could have left with one, but two made it impossible she would say). When they finally did it, and I finally found out, it was such a relief. In the end, it saved my and my siblings lives as my mother became more unstable. I'm not sure it would have improved her chances, but I do think if she'd moved back in with her parents when I was 9 rather than when I was 13 and my father had gotten his own place then that my siblings and I would have been better protected from the worst of it.
Some of the best things in life have risk - and 'staying for the kids' has its risks too. I agree that with DC it's important to consider things carefully, but I wouldn't take children appearing happy to mean that they haven't noticed or aren't affected it. That they seem to have a very different view of their father than you do I think is important to pick up on.