This was really good. I liked the sympathetic picture you painted of Maeglin - while he has his own reasons to oppose Idril's marriage to Tuor, he raises some sensible points here (even if he turns out to be wrong, fortunately). Idril's reactions were also very reasonable and sweet. This may have been the friendliest conversation between Idril and Maeglin I've ever read!
The Lohengrin inspiration was woven in really subtly (I was a bit afraid that it would be an in-your-face operatic reference before I read it! ;)), and I particularly enjoyed how you worked in the Hobbit quote.