I wasnt conciously trying to argue that ballast stability was inherently more stable than form - however I think in a roll-over situation a boat with high ballast stability will right more easily than one with high form stability.
Yes and no. The determining factor I think is the upside down shape and buoyancy, wide and flat flush deck is very stable upside down, wide with a raised coachroof and so on is not. The important thing is not to get upside down in the first place!
Sermons from my pulpit are with tongue firmly in cheek and without any warranty!