I feel you are overthinking the whole thing way, way too much. We shouldn't start to wonder about stuff that's really not relevant. The game is constructed really easy and it's always the same. Make somebody happy -> get the pussy. What Harold thinks is neither known nor really relevant. If MC fails to bring the family togther, as Mia wishes, but basically makes it worse, Mia should be upset, because that's in character, and because of that she should reject MC. The same goes for Mrs. Johnson. Get Erik a girlfriend -> MC gets her. It doesn't get any easier.
Well, you said yourself "half" of the town, which means that some choice may be an option. It won't be realistic and there doesn't have to be an explanation for everything, but I'd just like some individual characters and some depth. The story will never make sense as a whole (it's a porn game after all...) but there should be a degree of character credibility and consequence. For characters like Roxxy and Chrystal for example it's quite reasonable that they'd be willing to share at will, while the same would be really out of character for Mia and Helen, without a really long lead up, or even at all.
Or in short: Just because there are and will be some smaller or bigger inconsistencies in the game doesn't mean, that every bit of credibility should be thrown out the window.
You're wrong. What Harold thinks is important because he has the opportunity to present his motives to his daughter, which may affect what she will think about the breakdown of her parents' marriage.
MC did not have the slightest influence on the marital problems of Mia's parents, so there is no reason why she would have to ask him to solve these problems.
She can ask for help but she should not blame him for the failure of their marriage if he fails to fix it.
Blaming the MC for the breakup of the parents' marriage would indicate a lack of elemental logic and the association of facts by Mia.
What is credible is decided by an appropriate idea for the story and an appropriate presentation of events.
Example.
Harold decides to leave Helen, which causes her to slow her mental breakdown. Mia is worried about her, so she consults with a nun Angelica and Mrs.Ross because she has a good relationship with her and trusts her.
He gets advice that comes down to the fact that Helen should start going out and meeting people and especially with men, to restore her confidence and faith in her attractiveness (which suffered when Harold abandoned her for another woman.) Because Helen's life was reduced to help in the church and taking care of the house, she has no friends who could help her or know men she could trust and with whom she could go for dinner and ultimately for a date.
Mia only knows one guy who fulfills this condition and is MC, so he asks for help, specifically he would come more often to keep Helen company and sometimes go out with her for lunch / dinner or shopping.
MC agrees and after some time it turns out that Helen actually feels better. She regained her self-confidence, her psychological condition is much better but the risk of collapse still exists.
There is a new side problem for this. Helen fell in love with MC.
She told her daughter who now has a dilemma. She has to decide whether.
1. Stop the MC for yourself and cause a mother's mental breakdown?
2. Give MC to mother, which will cause her to lose hope of relationship with MC.
3. Share MC with mother if Helen agrees.
Now, if at the time of making the choice Mia will have a relationship with MC, and Helen will be aware of that, and MC and Helen will do nothing but her back, which would make her feel cheated, there is a good chance that she will choose option 3 and he will share the MC with Helen.
Quite a credible explanation for the triangle of MC, Helen and Mia with the consent and acceptance of all interested parties.
