Schutze, I'll try and answer your questions.
I can't see the question but I'm assuming that you think planes aren't that great against ships? As you have the demo try moving the French fleet up to bombard the germans in the low countries. The French fleet gets decimated by the land based bombers every time.
Yes I'd take that as give also.
I'm assuming again that you feel that the RAF is over performing in this game? I just can't see this as from my point of view Strat bombing is costing the Bristish more (in terms of production) that the Germans and I feel that is accurate.
They are critical they boost readiness and supply for friendly units, but you are right they can't be assgned to friendly units, the units that they get are chosen by the computer
I think you have to think about the big picture, a sub counter isn't a sub it could represent 20-100 subs (Italy in 1940 had over 100 subs but only gets the one counter). While a battleship counter is 1-2 BB and few CL and a dozen DD. I see the costs as about right and well balanced in terms of game play.
I've tried do that way too It makes sense thou you have an experienced unit at half strength and strengthen it with green troops it doesn't mater if you strength in slowly or quickly unless you see combat your still going to have a unit of 50% vets and 50% greens.
I hope that helps.