I am not a physics expert by the longest shot but let me answer the third question to the best of my ability...
General Relativity only deals with the larger bodies but when we try to apply it to subatomic particle, it breaks down. Quantum mechanics is much more accurate in defining the movements of these small particles. In this subatomic world, everything is governed by the law of probability, so it might be able sometime for some particle to travel more than speed of light.