I am a strong believer in the 1 fighter a turn method, at least until it becomes hopeless and you are just defending waiting for the inevitalble conquest of Berlin.
The scope of the effect the fighter or bomber would have is not only limited to an atlantic sea battle, although should the opprotunity arise you should seize it. Also, in your scenerio of having an over-whelming fleet you do not put any pressure on Germany for at least 3 turns. I am guessing you are holding your fleet back NW of Great Britian until more ships arrive. I would almost never attack the fleet you described. But if UK tries to land any troops (whether it be in Eurupe or Africa) before they can consolidate with the US fleet I will attack it (you can no longer hide from my airforce once you land somewhere). Also, you underestimate the power of the threat of an attack in the sea. Lets say that you force the UK or US to buy an extra carrier because they fear a german air attack. They just wasted 18 IPC. Yes, they may have a little bit more manuverability with the extra carrier… but that small perk is hardly worth 16 IPC (or imagine if they wasted 24 IPC on a battleship?). All the while you still have your versatile air force that can just go to another theater to inflict damage.
As to the 10 ICP fighter issue compared to the 3 IPC infantry… A slowly growing German airforce gives you enormous versatility. And in general the German airforce should grow because if the German player is playing smart he will covet his airforce and not squander it foolishly. An end all battle with the atlantic fleet is a once a game thing, that can very easily decide the game. But barring game deciding moves, the german airforce should stay in tact for the most part. Lets say it is turn 3. The Germans have taken Egypt, the UK put a IC in south africa. Pretty standard game situation. Leaving a token air force behind in Eurupe to exchange territories with the Russians, move the rest of it to Africa. Lets say realisticaly that is 4 figheters and a bomber (leaving 2 fighters behind in Eurupe). Now the stalemate going south turns into a route (I feel stupid at the momment and can not remember how to spell that correctly - sorry). You march down Africa and take the IC. You may say the Americans or British will land troops in africa, ok. Now you have your airforce there to destroy any invasion force that lands. Of course they may take thier planes off the carriers to protect thier land forces. I will attack the navy just because I can’t stand empty carriers lol. You can see the versatility of this I am sure. You mentioned rockets… they are nice, but if you go for a developement I say it should be long range aircraft. You at least double the threat posed by your airforce if you are lucky enough to get it. In revised, the map is bigger. The US player usualy uses Canada as its jumping off point to Eurupe now. With long range aircraft they need to put some serious defense there to protect the gravy train of troops that comes. If you get so bold as to get an extra bomber or 2, even the eastern coast of the US is not safe from the German airforce.
Airforce means versatility to the Germans. It has the range and the power to effect any theater of the war. You like infantry with the German, and lord knows you are right by knowing they will need them against the Russians. But you can not instantly transfer troops from one front to another the way you can airforce.
I know that you are going to say that given what I have said the allies going whole hog after Germany can take africa, and have the gravy train of troops coming into eurupe while putting pressure on Western. True, it is inevitable in that situation. But the key to victory than is to make it take as long as possible for them to do it. I never claimed Germany has the ability to defeat all 3 powers by itself. It can’t. But by correctly choosing your fights, and making every advance cost the allies in wasted IPC from fleet, or reconquering taken IPC in africa you delay them long enough for the Japs to run rampid through the rest of the world.
Last thing, a strategy I have used with my airforce towards the “end game” (meaning a dash to moscow) is upon making my big push to moscow I start it with a suicide charge into the atlantic with my airforce (suicide is relative, I mean going into the battle knowing I will lose my airforce to achieve time. Insane odds I won’t do this - but insane odds also means that I have made the allies over buy thier navy). If I can do an exchange, my airforce for thier navy I will do it (and buy 2 fighters that turn to keep a minimal threat to naked transports being placed). My airforce of course would be a great help in a russian offensive, but I will gladly trade them for 2 or 3 turns of “alone time” with the ruskies.
Keep in mind, I am not advocating the first turn buy being 4 fighters or something insane like that. Just 1 fighter or bomber a turn (and if you feel lucky go for long range aircraft). Germany can afford that, and it will play hell with the allies ability to move troops. A short coming of the game is that subs play nowhere near the role they did in WW2. A German airforce can play that historical role, if done correctly.