Thank you, Colin, for your insightful review. I agree with your assessment wholeheartedly. Even though Turin was far from Tolkien's most loveable character, he is certainly one of his most fleshed out characters, especially from a psychological standpoint.
As you note, it is full of allusions to both Germanic literature and, in small part, to Tolkien's own life.
A very powerful and moving novel, rife with important themes.