I don't know if this site will work out of the states, but this is where I have watched EVERY SINGLE AVATAR EPISODE at least 4 times I'm not sure if you'd still like to watch them, but here: [link] Hope it works!!
I think Naga's a little bit bigger. But it looks awesome anyway! THE NEW AVATAR IS SO AWESOME!!!!! Can't wait for the next episode.... Really want to cosplay her one day.... Time for a work out! PS, love your style.
Probably whomever placed restrictions on Korra's ability to run away from events.
This series was based in a relatively small area so she couldn't have a long distance flying pet. It had to be restricted so I figure it was important to have a creature that would focus on making you feel constrained. Also why she doesn't have control of Air just yet. Keeps her on the ground and vulnerable.