i think point 4 is the more important one- if you want a long term relationship, you're going to get old and if you get pregnant you are likely to get fat at least for awhile- and you can only control these things so much even with effort, some of it is genetic. having a partner who's picky about weight and youth = having a partner who will inevitably be dissatisfied and more likely to treat you badly over time. so it doesn't seem like something to optimize unless you're looking for short term wins like in sexwork.