If you don't mind the ugly, I would let the leaf come off on its own. That way you do not risk infection from the cut. if you do cut it off, be sure to apply a seal to the cut. The phal in the second photo will probably be fine. It looks like it has two good leaves and only one seriously burned one. The phal in the first photo was really burned. The leaf that is turning yellow at the base will fall off soon. Hopefully that will promote some growth.