Considering this is a male/female/multiple protag game, I'm not sure what the point is in declaring who you would prefer or not to play as. Yes, I get the Dev's earlier works were based on a female protag, but as this one is specified as both, I see no reason to shoehorn this into a similar nearly exclusive female/lesbian themed VN. While that and female protag content in general will obviously be a part of this story, from what I understand reading the OP, this is a story about a married couple, and not just the wife and their daughters.
As long as we're citing our preferences, while I like the premise, I'd personally opt to play as Mark almost exclusively if not as much as possible....and likewise when playing a female protag in a multiple protag game, I typically make choices as the female to the benefit my male protag. That said, to each their own, and ideally everyone would be able to play the story they want to see based on the Dev's vision.