Imo, reasonably limited replacements and some AoE improvements will be enough.
1st one needed just because the best frigate right now is fighter (except for Afflictor, Omen and other specialists). Fighter wing can do the same things, and if you lose it, you can just create another one. Pretty balanced, yeah...
2nd one is good, because you dont nerf fighters. If you stand against few carriers, your AoE will kill some fighters, but not too much. Especially if they attack from different angles. If you stand against a screen full of fighters, your AoE will kill a lot. It is natural counterplay to fighter spam, and making counterplay is way better than just nerfing things. Why AoE need to be improved then? Well, because right now PDs are not counterplay to big swarms. They are severe necessity for survival. While counterplay means "a way to win easily against thing X". I dont wanna my fleet to 80% consist of PDs and i dont wanna to fly to my colonies every time i need to face carrier fleet. I dont do that for any other type of fleets, why carriers must be so special?