A vacuum and a black hole are two very different things.
No, a black hole contains a lot of matter and thus has a huge gravitational pull. Absolute vacuum doesn't exist anywhere we know of.
Not necessarily.
After the black hole dies out, (see When do black holes die and/or How does a black hole get smaller) it will become just a vacuum.
yes. but the intense gravity is so strong it seems to bend time so slowly some people believe that there is no time in a black hole I WOULD JUST LIKE TO POINT OUT that time does exist in a black hole it is just extremely slow on another note if time did not exist in a black hole then a black hole would not suck things into it. so time does exist in a black hole.
Yes. Intermediate-mass blackhole is a medium size black hole. Scientists have found stellar black holes and supermassive black holes but there is no prove that Intermediate-mass black type of black holes exist. My opinion is that they do exist because when a black hole is becoming a black hole supermassiveblack hole it will need to go though this stage of intermediate-mass black hole.
No, the universe is mostly a vacuum but a black hole is (theoretically) when gravity goes wild and rips a hole in space and time
We know nothing about the conditions within a black hole, but it seems unlikely that a black hole could exist within a black hole, or even if this concept would have any meaning at all.
There is no evidence that white holes exist.
Since whit holes only exist mathematically, a black hole could not pull in a white hole.
"Absolute magnitude" talks about the intensity of light radiating from a source. The black hole is black because no light radiates from it. So you'd have to say that its magnitude ... visual, absolute, intrinsic, or any other kind of magnitude ... is infinite. (Magnitude numbers are higher for dimmer sources.)
Black holes, or singularties, apparently exist in different sizes.
No, the absence of matter would be a vacuum, which is quite different from a black hole. A regular black hole has a fairly large amount of mass (which is basically the same as matter) in a small space.