It would be nice to do to problem child provinces. If you set taxes to low and have 80 percent happiness from garrison and the city has a blue or red face you should be able to tear them down to decrease a chance for revolt but not an increase in happiness.

Tearing down walls of a city that was likely to rebel or did rebel was a classical way to kill revolts. When Carthage came to a rise in power they tore down all/most of the city wall's of cities they wanted under thier control and possibly cost them years later.