I think it would be good if players were able to transfer a part of their income or a steady cash flow (for example 20 cred/s) to other players. This would be useful in games vs AI, where a weaker player could be forced to transfer income to a stronger one - finally you don't have to destroy an enemy and recolonize his planets in order to boost your economy. In multiplayer games eco players could transfer cash to front line players without having to click the donation buttons all the time. Everybody who has ever been in an eco spot with >100$/s knows that you basically spend half of your time clicking on donation buttons (or please at least allow a way to transfer more than 250 per click).