though there is much i disagree with in your post, this one sticks out the most to me:
even moreso with she-ra. she didn't need a romantic interest. she was strong, independent, and completely capable -- all things i looked up to so much as a young girl. i'd say, if anything, young girls need strong women role models that teach independence and self-sufficiency without needing a man to make them happy. finding out you have a long-lost brother is incredibly emotional and can explain just about all of the responses you listed above. if they had been treated like barbie and ken in the show, i would not have been a fan, and likely many other girls also feel the same way i do. i'm not a complete anomaly! (at least, i don't think i am!)
at any rate, they did do a LITTLE with romance in the show with some of the characters having obvious crushes on others, but mostly it was in a humorous way. SO GLAD the whole show wasn't circulating around romantic relationships!
(incidentally, if a girl wanted to play with the dolls in a way that makes he-man and she-ra more like a couple than siblings, they certainly could. there's no signed agreement that you can't play with them like that.)