Hello! I never posted in the forums, but I've been reading for some time. This thread is very interesting! Cole is, for sure, my favorite Dragon Age character.
You've been discussing Cole's personal quest, and I feel like giving my opinion. Many seems to like the Spirit path, so I'd like to speak in favor of the Human path. Especially because some said it would be "wrong" to make him human, and I don't believe that.
First of all, Cole was a spirit of Compassion. Compassion felt sorry for the original Cole, and when he died, Compassion decided to be Cole, to live the life Cole couldn't. This means Compassion himself decided to be more human, to honor the forgotten boy.
By making Cole more Spirit, he ends up "making himself forget" Cole. He makes himself forget his own choice, his own "sacrifice," merely because it's painful. In the end, "Cole" dies.
Also, in his personal quest, Solas and Varric are biased. Solas only lived among spirits; his best friend was a spirit of Wisdom. Naturally to him they're better than humans. (Especially considering the Epilogue, he's not very awesome.) Varric doesn't want to see another Justice, a spirit corrupted into Vengeance. And we have already seen Nightmare, a possible end for a corrupted Compassion.
One thing is certain: Cole wants revenge (human path) the moment he sees the templar who killed the boy. To make him Spirit, you convince him otherwise. You're not "denying his nature." It is his choice. You're allowing him to grow.
If you think about it, look what happens in the Spirit path. Making people forget, including himself, is simply ensuring they will never learn and will commit the same mistakes. Isabela, of all people, has interesting views: "Our mistakes make us who we are." We learn, grow. How can we learn from a pain we don't remember?
Regarding Justice, she says, "Justice is an idea. It makes sense in a world of ideas, but not in our world." Compassion is also an idea. What keeps Spirit Cole from being corrupted in the future? Human Cole learns. He doesn't need the amulet. In Asunder, Rhys told him it was wrong to kill the mages. He understood, he learned. Can a Spirit learn, if it doesn't remember?
Some argued Spirit is his nature, and making him Human is a "mutilation." Consider point one. What is his choice? Let's analyze a similar situation: Krem.
We know Krem was born a woman, but what was his choice? To be a man. And people respect that decision. A spirit, Compassion, decided to be human, to be Cole; why not respect his decision?
He became Cole, he learned with Rhys, he wanted revenge for himself. He feels human. Why deny him that? Why force him to forgive the templar, if that's not how he feels?
He approves either way, but think about it: this means he approves not of which path you chose, but the fact that you DID choose and now Corypheus can't bind him. He approves because he is safe.
This is my humble, honest opinion. I felt like sharing today. Feel free to counter argument!