Yes - I knew "linge" for linen used in the context of laundry/washing,but not "lin" until I looked it up. Agreed about Deagol - I just like to think of him as the forgotten Ringbearer. After all, he had already given Smeagol a present.
I wonder if any Silmaril lore passed to Celebrimbor from his grandfather, and whether it's mere coincidence that they both made three of what they made. (Feanor possibly made the 9 Palantiri too, of course).
5. Barking up entirely the wrong tree, I'm sure, but the only real "enigma man" I can think of (unless you count why Beorn is sometimes a bear) is Bombadil. And I suppose he's endless. How the "tragic hero" could fit I don't know, unless his other name, Iarwain Ben-adar, is also the name of a tragic hero in another tale.
Unless - cutting the end off enigma was giving me no joy - perhaps it's "enigma man" one needs to take the scissors to. Synoynms of the term haven't led me anywhere, so ....