Some good points Battlingmaxo, and I suspect from a non-tech standpoint that is the best option for Germany, stockpiling the extra cash to use as needed. I am normally a tech player so I spend the excess on research.
As far as Carriers for the Allied fleet I think that is a good response up to a point but I think after a certain mass of carriers is reached the US is better served with Destroyers for fodder and the UK is better off with Cruisers to facilitate strafes using bombardments. That is from my German view of things at least. I do not play KGF with the Allies so I could be wrong.