Sunset

溶けていくわ
地平線沈む太陽
I agree, it def would be more of going thru time rather than distance. Don’t think I meant it literally “go away”, but in that it’s fading and not stopping. I actually don’t like how literal I am, and would switch the lines to “The sun slipping beneath the horizon, ever fading away”. I don’t like “continuing to fade”, while correct, doesn’t give the same sense of melancholy.

長く伸びた
手と手重ねるシルエット
Yeap, hated this line, hehe. The “重ねる”is the hard part. I visualized it more like the sun going down and a bunch of silhouettes sort of overlaying each other as they grow long, like connecting hand and hand. I suppose being personal is more romantic. Maybe something more like “Outstretched silhouettes overlap with held hands”

永遠の一瞬空に描いた
Agree, I was too caught up on the “一瞬”, I like your translation.

抱きしめられるのなら
もう一度腕の中
I agree, should add more emphasis, something more like: “If you truly held me, once more in your arms…”

淡く世界を染める
Sunset 私を包んで
Yeap! That’s a mistranslation, that’s def an adverb. “Faintly, world will be colored”. The random English “Sunset” in the 4th bar is hard. I can see it being the topic noun being loaded with the above 3 bars, that’s difficult to put to English, because I’d wanna put it up in the conditional part. What’s worse, that’s the hook, when an English speaker hears “SUNSET”at that spot, they like seeing it there. “You, the SUNSET” makes sense, but gets off beat.
“If you truly held me, once more in your arms, you who faintly colors the world, SUNSET envelop me.”

月に踊る
思いは行き交う波のよう
惹かれていく
このまま揺られていたいのに

I agree “Dancing in the moonlight” is a correct translation, I disagree with the second line. The “思いは”is too hard to overlook, especially pertaining to the first line loading it, “the thought of dancing in the moonlight comes and goes like a wave”, third line “it’s an alluring thought (at that)”. Fourth line “even though I’m wanting to be rocked like this”(regret note). I guess you and I might have a bit of bias and just know the “want/wish” is a regret, but somebody unable to hear the “のに”would need the somewhat equivalent “even tho”. I chopped it for rhythm, but it does seem important.

“雨の香り”
Absolutely right, in fact, love your full translation, it flows so much better than what I was trying to get at; stealing. “The rain's fragrance brings back old memories, I feel this deep sadness because I knew you”

“ありふれた日々が今
海の彼方へにじむ”
I’d keep the “now” in the first bar. “Fade” is probably an easier English equivalent to “bleed, blur, run smear away”. I think I want to keep the idea of the Sun in mind, blurring like a mirage on the sea, blurring away the days.

“儚く”
Yeap, another adverb, absolutely right. Hate how often it comes up too in JP, lol, not something we really use in modern English, that “fleeting, ephemeral” kind of feeling. Also, as with last chorus, the SUNSET hook has to hit at the right place.
I’d change it to “Now, the mundane days, blur away beyond the sea, you that briefly colors the world, SUNSET envelop me”

Chorus 1 Repeat
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Appreciate your input greatly, I'll revise the lyrics.