I agree, havent seen or played one game where the german player did not buy fleet G1, and i believe its because its simply the best opening. If you do not put early pressure on the brittish it will be too easy for them to stop Italy before they can grow to a decent ipc level. And Germany fighting alone is a lost cause unless you are close to breaking Russia.
I believe Larry Harris did try to fix this in alpha2, a G1 barbarossa now seems a viable strategy in itself. The problem is in my opinion that the mediterranean setup is too volatile. Theres a very fine balance between succes and disaster for the italians. That means Germany have to put pressure on UK if they want Italy to gain critical mass.
I would like sealion & barbarossa to present equal oppertunities for Germany, and i think the key to resolve that is to rearrange the mediterranean setup (again) and lower the ods for sealion a bit.
Apart from this i do agree that the game seems well balanced most places. Some of these balance issues are perhaps also a matter of taste. There might be some people out there who just love building german ships, but personally i like it when the game offers more than one option.