I always thought there should be "Dark/Light sides" of bending. Would love to see an evil Water Bender suck the blood right out of his/her victim which would be a really OP power BTW. I know we have blood bending but still.
I think that's specifically a dichotomy the first series tried to avoid. There isn't really a lot of good/evil characters in Avatar. Ozai is perhaps the closest to being more than simply an antagonist and into a villain, yet I never really received that vibe. Even Aang wasn't above lying to settle a dispute.
I liked the lack of preaching. Aang was a vegetarian and Sokka couldn't go a meal without meat, but neither tried to force a lifestyle choice on the other.
And while benders are very important and potent characters in the series, it was never so overly focused on bending that non-bending characters fell into insignificance. Edited, Mar 15th 2012 11:05pm by Allegory