Is the scab that forms on a wound impure, and does it contaminate dry water upon contact with it, and what is the ruling on purifying a floor and a mop if the عين النجاسة (substance of impurity) has not been removed, and what should be done in this case?

Satanic whisperings (waswas) have greatly affected you. We advise you to completely disregard them. The default state of things is purity, so the surface area and the bathroom floor are pure, and whatever touches them does not become impure. Delving deeply into matters of purity is an innovation (bid'ah).