how can a singularity be an infinetly small amount of space, when Planck Scale physics has a limit of size?

LURCH was speaking mathematically. You see as far as we know a singularity is a zero dimensional point, it has no width, breadth or height. This knowledge comes directly from the mathematical constructs of General Relativity, Einstein’s Theory of Gravity. The Planck length as you mention is the boundary length scale at which classical notions of gravity and spacetime cease to be valid and beyond the Planck length quantum effects takeover. At this point we really can’t say whether or not a singularity actually has some upper limit to its size or has no size at all. Our accelerators have not yet been able to probe the energies near the Planck length. Thus the only assertion we can make about a singularity comes from General Relativity and field theories such as Quantum Gravity, which is still largely understood. So to answer your question, maybe it does have size, but then again it might not. At this point in time we really can’t say.