I also looked at your reply to Human's staement. The rotation of the black hole (i.e., the singularity) isn't really that important. The singularity is infinitely small, so any discussion about its geometry is kind of a moot point. The event horizon, though, will always be spherical. it will pull infalling matter around it into a spiral if it's spinning, but it won't turn into a disk itself. It is a boundary around an infinitely small point, so it will always be spherical. And the coagulation of two black holes will not "relase" matter either. However, this does cause the newly forming, larger, hole to emit gravitational waves. And, of course, all the normal forms of radiation around a black hole are also present.