[Agent Night]

Even leaving her with just air bending and forcing her to work exclusively with air bending as she struggled to get in touch with the spirit realm to recover her bending would have been fascinating and a great way to lead into the next season.
I also completely agree with you on character development-I feel like Korra started out a head-strong young girl who acted before thinking and ended the season as a head-strong girl who acted before thinking. I really don't like Mako as a playboy who keeps two girls hanging due to his inability to choose between the two of them. I also thinking we could have had more time for character development if 1/5th of the season hadn't been devoted to the Korra version of blitzball.
To sum it up, while I would love to see the universe and social stratification tackled next season, I probably won't watch long too long if the writers continue to refuse to build the characters they've introduced