Regarding the transfering of najasah, if my arm became najis with urine, then my wet hand touched my arm and then a cloth touched my hand, all three of these things would become najis. The cloth would not be able to transfer the najasah any further.
If your arm became mutanajjis with urine, and your wet hand touched it without transferring the actual urine particles to your hand, then in this case your hand is mutanajis 2, and therefore the cloth is mutanajis 3 which does not cause any further impurity.