It seems very weird to me that in order to create a current and have conduction, you need to actually put a resistance/conductance in a circuit. That is, a perfect conductor itself will not carry either a (finite) current or a voltage.

From a engineering point of view this sounds wrong and non sense. From a physics point of view, this is because in a perfect conductor charges will immediately distribute themselves in order to cancel out any voltages created, therefore voltages cannot exist unless a resistance to charge movement is inserted.

The case of currents however seems more complicated... A voltage applied to a perfect conductor from end to end, would create an infinite current rather than a finite one. But what is correct to say? That there is no voltage, or that the current is infinite ? The question is, a perfect conductor will not carry a current because any voltages applied to its ends will instantly cancel out, or because the current will be infinite?

Anyways it sounds weird to me that in order to have a current, one needs to add a resistance to the circuit. It doesnt sound as weird if the resistance is seen as a conductance, but then a perfect conductor is the best conductance.

What happens at the atomic level when a voltage is applied to a perfect conductor?