I agree with you that a happiness buffer should be expected when expanding....to me happiness is the barrier that you have to overcome to warrant a new city, so that makes complete sense. I do not agree with population. Simply put, I fundamentally reject that stopping growth should be a core happiness management tactic. I think its prudent when you get a happiness bomb, such as when you get sanctioned and all of your luxs go away or are in a long war and your war weariness is creeping up. In those situations it makes a lot of sense to have to limit growth to address your "crisis" needs. However, if I'm just building along (especially if I am doing nothing but building), I should not need to stop growth in order to keep my cities from the throes of unhappiness....that to me is a scenario where the happiness system is not properly tuned.