Oh, it does vary a lot from relationship to relationship. Some transition better than others, but even a slight nuance can utterly change how people see a relationship. Take for example Avatar, where I’m pretty sure that if Aang were two years older and an inch taller than Katara, the complaints about how she is too much of a mother to him would evaporate.

As for Sasuke and Naruto… I tend think that if one of them were a girl it wouldn’t really change much.

Kiba’s hair… I don’t think so. From what I remember it’s as unruly as ever.