The poke through on the elbow is most likely a combination of things, firstly make sure smoothing is off before you simulate, then change the collision mesh resolution to viewport, as the base mesh and the subD mesh can have fairly large differences around bends/curves. for a generally better simulation I would also set the collision mode to best - Continuous : CCD, as this will detect collisions that CCD Vertex-Face can't. I would also suggest setting frames per second multiplier to 4 (this will make the sim take longer but I find the result to be better/more realistic).

For the poke through on the heel I'm not sure, watch the simulation and see where it starts poking through, sometimes a current frame simulation with pose transition is not enough and you'll have to use a timeline simulation to manually edit the pose change.