If the amount of gravity from a black hole were pointed in just one direction, what would happen?
Well... that's sort of like saying "If a circle was square, what would happen?
Gravity, as best we understand it today, is not "directional" in that sense. It's always omnidirectional... a "deformation in space/time" with the deepest deformation at the center-of-mass of whatever mass is creating it.
The model usually used to describe gravity is to think of 3D space as 2D... and as a big sheet of rubber (infinite in size, but for the purposes of this discussion, just assume that it's a square several feet across with the edges supported, which is "good enough" for now).
Then think of a series of heavy spheres... representing various objects with mass. Put them on the sheet, and they locally deform the sheet, creating depressions in the sheet. Other objects also deform the sheet. These deformations affect other objects, of course. If two objects are very far apart on this sheet, the effect is minimal. But, put a big sphere in the middle, and several smaller spheres reasonably nearby, the big sphere will "attract" the smaller ones, due to the "incline in space time."
That's quite literally about the best model we currently have for how gravity works. As for the mechanism behind it... nobody has developed any reasonably model, with any mathematical support or experimental support, to explain that. We have no evidence of "gravitons" or "gravity waves" or anything of that matter... none whatsoever. A few people have written dissertations talking about such "hypothetical" particles or wavicles, but none have any support at all at this point.
We understand "If this, then this" quite clearly at this point, insofar as the attraction mechanism works. We get this because of the relative ease of collecting data on how it works. We have equations which very well explain "if this happens, then this is the result."
But we really do have no idea how we get from point A to point B.
What we do know is that gravity, as we understand it today, is omnidirectional. If it were to somehow in the future be determined that we can direct gravity in some manner... well, it may be possible but that would be something far beyond our current understanding.
So... the answer to your question, really, is "nobody has a clue." :freak: