Is there any hope of redemption ...?

[The Saucepan Man]

The discussions on various threads, in particular Iluvatar's opponents and Original sin in Arda, have got me thinking ...

Is there any hope of redemption for evil deeds in Arda? I am not talking Elves here, because I understand that those who stray from the path tarry a for a long while in the Halls of Mandos. I am thinking more about the Hobbit/Human characters. Thiose who are given free will, but exercise it wrongly.

I can think of a few candidates:

1. Borormir: As we all know, he attempts to steal the Ring off Frodo by force. His final act, desperately attempting to save Merry and Pippin, is a valiabt one. But Boromir is a noble character who acted, albeit misguidedly, with the best of intentions - to save his people and defeat Sauron. So, he was never intinsically evil. Did he need to be redeemed and, if so, was he?

2. Gollum: Possibly not originally an evil soul, but corrupted by the Ring. He is driven by his desire for the Ring and, notwithstanding Frodo's kindness, his purpose throughout LotR is, in my opinion, to prevent the Ring being destroyed and, if possible, seize it for himself. Is he redeemed by his final (involuntary) act?

3. The Dunlendings: Not an evil people, but Saruman used, and encouraged, their grievances with the Rohirrim to enlist them to his army. After Helms Deep, they make their peace with the people of Rohan. Does this redeem them?

4. The Haradrim, Southrons, Variags, Easterlings and Corsairs of Umbar: Enlisted by Sauron but, again, were they really evil in the first place, or just corrupted by Sauron? Presumably, they too made their peace with the other nations of Men following the War of the Ring. Again, do they find redemption?

5. Wormtongue: Having been corrupted by Saruman through his lust for power and for Eowyn, he acts as Saruman's spy at Edoras and, for a while, is able to neutralise Rohan through his influence over Theoden. When found out, he runs off to Saruman, but is ultimately the instrument of Saruman's downfall. Does this act redeem him?

And there are other characters too, Ted Sandyman and Bill Ferny for example, who are less than sympathetically portrayed, but never have an opportunity to redeem themselves.

So, basically my question is - do any of these (or any other wrongdoing) characters get a shot at redemption? If so, which ones and why? If not, why not?

I have done a search on this topic and not turned up anything directly on topic. But, if there are any threads that touch on this, I would welcome the link.