Torpedo bombers -
Why NAVs are in the game, and torpedo bombers are presumably not, I have no idea. Torpedo bombers actually exist, and were extremely important in taking out ships. The reason why NAVs are so hard to balance is because they cover huge areas of ocean and do incredible damage for no particular reason. Not to mention that because carriers can't carry planes, ships have no defense other than land-based air. Torpedo bombers would allow for more direct, hull damage, as opposed to shelling and bombs having a relatively higher affect on org (damaged guns, flight deck, fires, and general mayhem). And that leads to...
Torpedoes -
Screening vessels should have more to do than simply get shot at. During the first hour of combat, they should unleash a torpedo salvo. They should be extremely inaccurate, but you should still have a chance to get a lucky hit. Torpedo tubes can be an upgradable part of the ship, having the ability to launch more at a time, and have greater range. It also allows modeling of Japanese ships, which generally had many more torpedo tubes than others of their class.
A torpedo attack was the main offensive ability of destroyers. They should indeed have the ability to attack, particularly at night, and be fairly dangerous. Making fake or real torpedo runs is vital to them bing a bit more than simply an ASW asset.
As for NAVS, only 2 countries made shore-based aircraft specifically for naval attack; Britain (the Beaufort) and Japan (GM and G4M). IMHO these should be seperate from NAVS which seem to have been employed in Recce and ASW roles.
I think it should be doctrinal. The ability to use TAC, SC and so on for naval strike should be basd on whether you have researched it or not. It is not just a matter of having the aircraft, for example Italy in 1940-41 did not even have AP bombs for her planes. Training in sea attack and navigation are also important parts of the mix.
K