Nobody knows, but most probably the enormous gravitation of the black hole(which traps light in its core, therefore it is black from outside) breaks down every material to its very elemental pieces
No, dark matter is quite a different kind of thing. A dark hole may have absorbed some dark matter, but pressumably that would become indistinguishable from the normal matter, once it gets crushed by...
Black holes are made just before a star dies. The stars core radiates outward pressure to balance out the gravity pushing down on it. When the cores energy runs out gravity gets the upper hand and...
Despite what you may have heard, the answer is no.
We can't make artificial black holes, but there probably is a black hole being created somewhere in the universe.