The BMI increase for immobility has been released now, along with a new 'barely mobile' category. I had been thinking about using terms like obese and morbidly obese for the categories, but in the end decided against it as they're already linked to BMI ranges medically.
I think your idea of interactions between the girls has promise. I'd like to make the dates more varied as they can get repetitive. That variation might include random events that occur during the date & perhaps if another girl you know is already at the date location, she might get involved. Could lead to say... a threesome?