Aang's actor looks nothing like Aang. Just sayin'.

I don't see why they can't typecast a fantasy setting with real world parallels. Sure there aren't many dark/tanned skin people with blue eyes. Why don't they just get tan skinned actors, and give them colored contact lens? Unthinkable, right?

The cultural inspirations are glaringly obvious, and I don't see why they didn't just recreate it besides marketability. The Air Temple has Shaolin inspirations out the wazoo, same with the Southern Water Tribe with the Inuit, Fire Nation with Han Dynasty Chinese. A bit unsure about the Earth Nation.

I feel a lot of the actual draw, and amount of immersion I'd get from a film like this is lessened immensely because they didn't cater to be as close to the original vision as possible, and instead chose to go for better marketability or some director's own folly.