as far as lack of development, because hinata was so shy it kept her from having many real conversations with naruto, that it just how her character is. She doesn't talk much to anyone even in shippuden. She talks mostly to neji who is dead. But probably now has more words to and about naruto than any other character. Shes not the kind of person to talk to naruto just because she likes him. Even after the confession she would never have confronted him about it and naruto didnt really have time for romance since stuff kept happening back to back. It wouldn't make sense for hinata to be put on naruto's team, because she belongs to a team already, and even so it would just make it awkward between the to, and if she switched pre confession she would have been just like she was in that bug episode in the original series. As far as development sakura hasnt changed that much, she changed once in the forest of death by deciding to try to be useful and then, became slightly nicer but besides that she is the same character. While characters like neji, hinata, jugo, and zabuza/haku have shown far more changes and effects on naruto. Infact she besides him liking her she has had little if not 0 effect on naruto's character development. I would say the same for hinata i guess but now she is stopping him from going of the edge so in a way she just cashed hers, but sakura still hasnt. The only way she can motivate him is to cry and beg him to fix her problems.
