A dimension is a measurement. A line is one dimension, a square is two, and a cube is three. A singularity is zero-one dimensional. Don't think of "different dimensions" as in "different universe." But no, I don't believe that to be true. A black hole is a just rip in space time. Don't think of it as a hole per say, it's still a spherical object, it's just that light cannot escape. It doesn't lead anywhere, it won't teleport you anywhere, it will just rip you apart and eventually evaporate. A black hole has two intrinsic properties: mass and spin. That's it. Black holes are actually pretty boring objects, what science is interested in is what happens [i]around[/i] the black hole. And the singularity is just nothing we can even talk about. FTL travel is fine, if you're not actually traveling faster than light. Like, galaxies do it all the time, as they're not moving away but space is expanding at a faster rate than the speed of light. So, if we can manipulate spacetime so that we could travel that fast, then yes it's possible. And presumably yes, about the looking back thing, although I'm not sure if warped space time would change this matter.