Well your question was if he could escape the "inescapable" pull of gravity by the black hole upon entering the black hole, ignoring many, and I mean, many factors that are going there. FTG can escape the black hole simply because it is a haxed jutsu capable of bending space and time making quantum tunneling with physical bodies possible. FTG is not possible in real life, as there cannot be physical teleport (Due the mass of a body increasing to infinity as they approach light speed). Though bodies cannot obtain light speed, it is possible to bend space/time around you to go faster-than-light (postulated by Alcubierre). Seriously, FTG is completely broken, as quantum tunneling of such potential would sent Minato back to the past (which he may be doing, as far as we know).
Now, if you ask me what is faster, the gravitational pull or FTG, then that is just pure science fiction and cannot be answered. I gave you the simple answer without any other factor on it. Theorically, we don't know how long it would take to reach super-singularity, as the black hole infinite density and size to matter for the equation, and equation that we don't have as far as I am concerned. If you wanted to be more specific, what kind of black hole? static? Kerr? lol.