Here’s a quick follow-up post on physics.
I’ve spent a lot of time doing various rigid body and smoke tests, just to get comfortable with physics in Blender.
I also tried to stress test the tools by using large amounts of active rigid body objects. That last clip with the round church tower collapsing consists of just bellow 10 000 active objects simulated by Bullet via the game engine. Both Bullet and Blender handled that many objects surprisingly well!