But there was still chaos left over in the world from Vaatu gaining strength and Raava losing strength, which led to humans fighting and eventual merging of Wan and Raava.

Hmm, she said that every harmonic convergence they would battle and I pretty sure she said that whoever won would be dominant and the loser would be absorbed, growing stronger until the next convergence.
She also said it more elegantly.

I don't think it retcons the origin of bending, rather than differentiate that human got bending from the lion turtle, but learned it (or its proper use and form) from the animal/moon and ocean, who do it naturally.

Dude, a lot of propagand films are like that. Haven't you ever seen In Der Fuhrer's Face?
http://www.youtube.com/watc…
Or You Natzy Spy by the Three Stooges?

Exactly. I was waiting on Naga to close her mouth a little more and then a pan down to the guys wet trousers. Then I remembered this is a kids show.

I tend to give Korra Book 1 a pass since they didn't know they were getting another season until production was well under way.

At this point, I'm just going with the Avatar State is slightly different for every Avatar?

http://25.media.tumblr.com/…

She acts like that kid who goes to like one martial arts class, gets maybe one belt, than thinks they're an expert.

Also the plushy air bisons. Who'd I hafta murder for one?