Excelent idea Math, I would add some "extras" over the already good sugestions of TAC.
Make the ships as damagables as airfields. Depending on the hit zone, acks would be destroyed, or radar, arrestor wires, course control, main guns, the deck itself destroyed, firing control for battleships, engine stopped, PTs dissabled, LTVs dissabled, aircraft dissabled, troops dissabled, ordenance dissabled, fuel dissabled. Make the ships much easier to damage but much much harder to shink.
Make the repairing of the ships an extremelly slow process (hours) unless they are near a friendly port or an army of goons drop a lot of goodies over the task force.
Also make the enemy TGs visible on map if they are in visual range of a friendly base.
Perhaps, even make the CVs capturable. If you kill all the TG acks, stop the engines of the CV and drop 20 troops over its deck, TG surrenders and is captured. Reasingning it to a friendly port while its previous port keeps inactive until TG is recaptured of shunk. This way you can strike the TG with small bombs just to neutralize its defenses and try the surrender/capture, or strike it with big ones just to shink it.