- no manaBiggest new features should be:
- redoing colonisation
- redoing trade
- the demographic and economic damage of war should be more punishing. Manpower losses. Add refugees emigrating war torn areas. Preserving peace from time to time while war rages around you should be a viable strategy. This would add another diplomatic/espionage layer where you could provoke war between neighbours to your benefit.
- minority religions and cultures
- better proportions in map (not-Europe is WAY larger in reality than in game).
Your third point : I've got the impression most people already restart after losing one war, something like this would have to be thought through very well to not make that issue worse...