...then stop conquering cities. Or annex them and take the hit to your social policies. There is another thread on the general discussion forums discussing the lack of important decisions in Civ V. Well, here you have a series of important decision to make and priorities to figure out. Do you conquer, or do you focus on developing your small empire. Do you puppet for the sake of your social policies or do you annex for finer control? You seem to want it all, unless I am misreading you. If control and social policies are your main priorities, the best path for you would probably be to forgo conquest in the first place.