Alto may have not known about the cookies, but he probably knew enough that Ranka wants to see him and so sent Michael in his place. Also, choosing Ranka was not meant to be taken as not choosing his dreams to fly...Ranka hasn't held him back from doing what he wants, except if he stayed on Frontier to enjoy his birthday with her, he would have to face the wrath of his dad or something for choosing Ranka over his wishes. Maybe he didn't want Ranka to think or get more problems if she gets sucked into a Saotome fight of epic proportions? Meh, just my humble opinion of course. Anyway, Ranka always tried to do her best to act for herself ever since Alto encouraged her to sing. Problem is, she is still held back be her feelings of doubt about her talents, her now slowly climbing singing career and coupled with her seeming infatuation or developing love for Alto. No wonder she acts weak, useless, and is too much of a moeblob to do anything to people who do not really like her character that much. Ranka has all those things going on at the same time, and she also has no memories of her past and tries to live with it the best that she could.