This is very interesting. Is there a theory (or... observations of sorts) on the interaction of anti-matter with black holes?
Black holes eat everything. They don't care about the differences between types of particles. It's all food
Also... while there is a "limit" theorized for speed (that is, c), has such a limit ever been applied to a force.
Yes. Every known force in the universe can be seen as being transmitted by a particle (photons for electromagnetism, gravitons for gravity, and so on). As particles, they are limited in speed.
With all this talking of black holes, the thought came to me, is it theoretically possible for a black hole to attain "infinite" gravitational force?
Um, yes and no.
The force of gravity one feels from a given object is dependent on two things - the mass of the object, and the distance from the object. Specifically, the force you feel goes like 1/d^2. So, if the object is really small, you can get really close to it, and the force you feel gets really, really big.
This is what happens to black holes. When the star runs out of fuel, the pressure of the outflowing energy drops off, and stops holding the mass of a star up, so it begins to collapse. If the star has enough mass, there is no force in the universe that'll stop that collapse. Ever. It collapses down to to the point where at the surface of the star, the force of gravity is so strong that even light cannot escape from the surface. The force isn't infinite, just very strong.
But the collapse doesn't stop there. Nothing stops it. It just keeps going. We can't see it, but it just keeps on collapsing down to a mathematical point - at that point, technically the force of gravity on any object would be infinite.
And if this is the case, would it be sufficient for the "Big Crunch" (if i remember the name correctly) to take effect.
No. But that requires some explanation.
As far as we can see, the Universe was born with some total amount of energy. No new energy has ever been created - it just swaps back and forth between being energy and various forms of matter. Whether or not the Universe will experience a "Big Crunch" depends upon that total, not on local conditions.
Black holes are just one place into which some of the mass/energy falls. It doesn't create "more gravity" by doing so. At large distances, gravitationally a black hole and a star of the same mass look the same. It is only when you get close to the hole that things get weird. So, the universe as a whole doesn't care if you have a black hole or a bunch of stars.