Most people know about the broken combo of Song of Eärendil and Wandering Took so I won't bother explaining it. I am not doing anything new here, but I think this is a deck that finally makes use of that combo for the biggest impact on a team. This deck is terrible for solo, but on a solid team that can take advantage of low threat this deck can provide some quality questing while lowering the threat of the entire team. It works best with other broken power decks like something that abuses Boromir or Gandalf/Elrond or doom cards and Gríma. Yeah, you have to have a high tolerance for OP.
The strategy of the deck is to use Galadriel and her toys to find the best cards. Hopefully you discard Elven-light along the way and you can use that to draw even more. You can also discard Elven-light to Steed of Imladris, To the Sea, to the Sea!, Protector of Lórien, or Glorfindel. Hobbit Pipe also draws a lot. Once you get rolling, you can draw a ton of cards fast, using Will of the West to recycle your deck for maximum threat reduction. Use Resourceful to play all those cards and use Good Meal to reduce cost on The Galadhrim's Greeting. Before long you should be at 0 threat and you can use the broken combo to drop the threat of all your teammates as well.
The key to making it work is Strider on Merry, allowing him to quest and boosting his willpower while also keeping him ready to drop threat. I think it works much better than Hobbit Pony. With Strider Merry the combo can consistenly allow to absob the threat of a 3 or 4 player team. In order to maintain the 2 willpower bonus you have to stay at 5 characters, but if each character is high impact it should work. Luckily you can send the took wandering and the rest are heavy hitters.
I have never included a sideboard on a decklist, but I did on this one because the decklist is really a suggestion and the deck shines once you modify for your team or quest. This is a great deck to support a tactics Aragorn deck, for instance, as lower threat keeps more enemies in staging. In that case, Tale of Tinúviel can be huge. Are you facing a Mumak? With the threat reduction you can ignoring it, but if you want it dead, how about throwing it under the deck with O Elbereth! Gilthonial!? You can probably more than handle the threat cost. Need skrying? Normally that is a challenge in multiplayer, bu this deck can quickly become a Palantir support deck. If you need more combat capabilty you can bring in OHUH Gandalf and or Arwen Undómiel, depending on what your friends are running. Speaking of friends, this should be popular with most groups because it let's others do the heavy lifting and avoids the inclusion of most popular uniques, including Steward of Gondor, opening up a ton of fun possibilities.
I hope you will have fun trying it out!
Ally Elfhelm would be a pretty good card to include in the sideboard for use against quests with a lot of threat-raisers, too.