Your post is very challenging.
Some old ideas and new ones together.
I like the carpet bombing roll @2.
No retaliation seems a bit overpowered.
2 attack @2 first strike is more powerful than 1 attack @4.
For medium bomber: Maybe 3 attack @1 first strike is comparable to 1 attack @4
For heavy bomber: 2 attack @2 first strike is comparable to 1 attack @5.
Or, drop the no casualty retaliation.
So you can keep the equation: dices roll= damage dices : 1 medium bomber: 2 dices, 1 heavy bomber: 3 dices.
Heavy bomber move is too much, just keep it at 7 spaces +1 with Airbase.
I also notice this feature:
As OOB, except subs cant sink other subs, and destroyers negate subs on a 1-to-1 basis.
This is another way to have less Subs as sea-fodder.
These combat values are hard on planes but it is a simplify scale A1 D0, A2 D3:
1. One round only of Air-to-air dogfight
Escort fighters att at 2, intercepting fighters def at 3.
All types of attacking Bombers roll 1 in the dogfight. Def Bombers roll 0
The missing part is about Naval combat with planes.
1 Carrier will put on board 2 TcBs for A6 D8 (same as 2 OOB Fg units)
2 Fgs are very weak A4 D6 (2*1 Fg A2 D3).
Carrier operations and naval combat already better in defensive and they now lose offensive power.
Now the offensive capacity of 2 Fgs (A4 D6) or 2 TcBs (A6 D8) or 1 Fg +1 TcB (A5 D7) is weaker than OOB 1 Fg + 1 TcB (A7 D7).
A single round dogfight phase, is it enough to outweight the above?
1 Fg A2 + 1 TcB A1 against 1 Fg D3 + 1 TcB D0 or against 2 Fgs D3+D3
This show how Fg is good on defense.
Because of this, I think TcB should get D1 in air phase also (still 3 times lower than Fg D3).