Lovely overview! Quick correction, though: Lindir wasn't created just for the movies. He was a minor character in The Fellowship of the Ring, often thought to be an elven minstrel (book two, chapter 1: Many Meetings). You'll find him mentioned in the scene with Bilbo in The Hall of Fire, after Bilbo recites his epic poem to Frodo and the rest. Lindir teases Bilbo that he can't tell the difference between Hobbit poetry and the poetry of the race of Men.