What is the ruling on purifying clothes defiled with urine on a dry bathroom floor, and is the bathroom floor and what comes after it considered defiled by the transfer of water that touched the clothes to it, and what should be done about that?

This question indicates a waswasah (whispering from Satan), and one should ignore such whisperings and not pay attention to them. When in doubt about the transfer of impurity from one object to another, the default is that it has not transferred until certainty to the contrary is achieved. The default is that the aforementioned items remain pure as long as you do not know with certainty that they have become impure.