The only real issue I have with Aiden is:

[quote]His speciality is making compressed [b]waves capable of cutting through even the hardest stones[/b] and shaping ice although he can still use more basic ways of bending with ease as well. He simply uses this technique more often. [/quote]

Ice shaping itself is master-level and the only people we seen canon capable of stone-cutting water waves are masters. He's had no formal training. I personally wouldn't want to see him with even one-high level technique due to the emphasis on culture, but two of them is just a bit overboard. I could justify letting him use ice-bending, but I do believe the capabilities of his water-bending do need toned down.