do you have any plans for destructable objects/levels? Would it be much work to add something like this?
Destructable objects isn't really something the physics engine would handle. To make them, just track the 'health' of the destrucable objects, then when it reaches a certain point, remove that object and add in some broken pieces where the object was. The physics simulation can then make those pieces collide with eachother, fall, etc.
Before Ask how to remove a body, you first need to Ask how the bodies actually get added to the physics system. The Phys System currently maintains a list of bodies, each body is added when you call the EnableBody function, so its prepared for the next "integrate" call. By calling DisableBody(), its automatically gets removed from the list.
About the "destructable Objet", I probably will do just what Anonymous (76.170.117.x) said, perhaps adding Skinned Animation to the explosion. You can always try to make a rigid body dynamic by using joints, but an explosion probably will be too costy for the CPU.