[The Saucepan Man]

This assumes of course that Orcs have souls.

I hold that they do. Whatever thoughts Tolkien may have had later on the subject, they are clearly, to my mind, portrayed in LotR as rational beings with souls. If nothing else, the conversation between Shagrat and Gorbag in the Tower of Cirith Ungol establishes that for me.

Since no fea can be annihilated, reduced to zero or not-existing, it is no[t] clear what is meant. Thus Sauron was said to have fallen below the point of ever recovering, though he had previously recovered. What is probably meant is that a ‘wicked’ spirit becomes fixed in a certain desire or ambition, and if it connot repent then this desire becomes virtually its whole being

Yes, that makes sense. I can understand why Sauron should not have the opprtunity to repent, since he chose to follow the path of evil of his own free will. But the Orcs never had any choice. They were born evil. So how can a "good" divine being deny them the opportunity of redmeption in those circumstances?

And dying they would go to Mandos and be held in prison till the End.

This might be interpreted as suggesting the opportunity of repentance following the Dagor Dagorath. Although, even if that were the case, it still seems unfair that they should have to wait so long when they had no choice in the first place.