another bug: GC6 earthquake
Has anyone else had the game fatally freeze on them when they pray to Silva on GC? This has happened to me many times.

Yes. I think somebody reported it already (I or someone else), but maybe not. The game probably tries to find a random rock ("cave" cell) which earthquake will destroy using an algorithm "find a random cell, if it is a rock stop, if it is empty repeat" ... and on GC6 it obviously freezes, because there are no rocks. Just don't pray to Silva on GC6.