OK, so I've had a bit more time to play with your mod now, & these would be the suggestions I might make for possible improvement:
-allow health bonus for food diversity....either within a city or empire....& allow food resources to be tradeable (as they were in Civ4).
-either change the bonus for surplus health (maybe a production/culture bonus) or curb some of the food bonuses for some of those buildings that boost health (like Aqueducts & Hospitals).
-aside from a chance of plague, perhaps negative health could have a similar effect to what it did in Civ4 (not sure exactly, but I think it was something like each population point consumed double food....or something like that), or perhaps a production/culture penalty.
-maybe outside of your bailiwick, but I'm also thinking that the Ideological Tenet for Universal Health needs changing-perhaps an across the board reduction in plague likelihood, plus a bonus for hospitals (maybe +2 tourism or gold in Freedom; +2 culture or happiness for Order; +20% HP's for Cities-& units stationed there-with a hospital or a medic promotion for any unit built in a city with a hospital for Autocracy).
Anyway, just a thought....but I do love this mod, it's brilliant!
Aussie.