3) In the end, she doesn't sleep with the doctor, but she also never reveals any of her interactions with him to her husband, and she chooses not to because her husband changed, implying that she was swayed by his character changing. This is completely unrealistic.
4) Buying her flowers and keeping his temper in check are good for their own sake, and a minor point of the movie, but they'd not have any effect on her behavior long-term.