I personally think Thranduil should get his armor automatically through leveling up instead of receiving from Galadriel, it is not very lore friendly.
Yes, it's absolutely not lore friendly, like other things in the Edain Mod, which though have some valid reasons behind them.
I regard it more as a wise gameplay solution, as it could be seen as a symbol to remark Galadriel's role as the Leader of the faction and most important hero, not to mention, also, that it was quite obvious implementing Thranduil's armour this way, one of the most logical solutions, I would say; better than a further ability of Thranduil, replacing maybe other ones more significant.
Concerning new power Elbereth Gilthoniel, is somehow possible to make lower background music in game while effects of this power lasts, so sound effect of this power became dominant?
Although you have already been answered by Ealendril under a technical point of view, I think that the sound of the Song must legitimately be the core of the whole spell, since it's indeed the Hymn of Varda, what everything is about
Also, I would like to congratulate with Ealendril and all the people involved in the beautiful outcome of this spell in the game.
It really gives the sense of the 'Nachtatmosphäre' element discussed in the German forum