What to do with enemy buildings

[AntiochusIII]

Of course, you may not be able to do that: roads, for example, can't be demolished and many barbarian/nomad factions lack the ability to improve existing (Roman) roads.

Is there a way to mod indestructible buildings...destructible? I rather hate late-game conquests of civilized factions because of all those huge cities and their gigantic Palaces. If not, is there a way to mod the % of Cultural Penalty such buildings can affect?

I hope so.