First i would like to say...awsome job with the game , but i see some issues with the carriers.
First i would like to adress the commander skill "Air Supremacy"...you get 1 bomber and 1 fighter ekstra, this is kind of a big plus to the American carriers as their "main" damage dealer is the bomber, but the Jap carriers mainly use torps...so maybe it needs a fix
Secondly i seriously think the planes need to be buffed health wise, the AA on the ships need the be reduced or the carriers should be allowed to carry more planes in their cargo. The planes get shot down REALLY fast with AA guns and you often return with 0 or 1 of their 4-6 planes. As a carrier i stay away from American ships and try to hit the Jap ones instead as they have the worst AA of the two (not that its not still enough to hurt my planes badly)
Third is the torpedo issue...your average torp (tier 1-5) deal around 6000 damage and around 10000 damage (tier 6-9), now thats not bad...but considering a destroyers torps deal 6000 - 24000 damage with a MUCH shorter arming time. Also the ranged is very different and the number of torps you can use is generaly a destroyer can use 1 "broadside" of torps every 30-60 seconds and he can spam as many as he wants at a distance of up to 20 km.
I think the carrier planes need some looking into, thats just my thoughts so far