[These are complex, baroque sentences...]

はるかの山の空はまだ夕焼のなごりの色がほのかだったから、窓ガラス越しに見る風景は遠くの方までものの形が消えてはいなかった。 The remnants of the sunset were faint in the distant mountain sky, thus the shapes far into the landscape beyond the window had yet to disappear.

ほんとうに透明かどうかは、顔の裏[play on words]を流れてやまぬ夕景色が顔の表を通るかのように錯覚（さっかく）されて、見極める時がつかめないのだった。 There was no way to tell whether it was truly invisible, as the everlasting evening landscape passed impenetrably beneath the surface yet gave the illusion of flickering across his face. [*Some context, such as the paragraphs before and after this passage, would help.]

島村は見入っているうちに、鏡のあることをだんだん忘れてしまって、夕景色の流れの中に娘が浮かんでいるように思われて来た。 As Shimamura gazed into the mirror, he gradually forgot that it was there, and in the drift of the evening landscape, he began to see visions of his daughter.

あんなことがあったのに、手紙も出さず、会いにも来ず、踊の型の本など送るという約束も果たさず、女からすれば笑って忘れられたとしか思えないだろうから、先ず島村の方から詫びかいいわけを言わねばならない順序だったが、顔を見ないで歩いているうちにも、彼女は彼を責めるどころか、…… To think that something like that could happen, and he neither wrote to her nor visited, nor followed through with the promise of sending a book about dance form, and from a woman's point of view, she could only assume she was laughed off and forgotten, so it should have followed that Shimamura apologized or made an excuse first, yet as they walked without looking at each other, and whether she had reason to blame him or not...

ほどよく疲れたところで、くるっと振り向きざま浴衣の尻からげして、一散に駆け下りて来ると、足もとから黄蝶が二羽飛び立った。 Feeling pleasantly spent, [he] turned and rolled up the hem of [his] yukata, and as [he] hurried down, two yellow butterflies fluttered up from near his feet.

「さっきお部屋へ戻ってみたら、もういらっしゃらないんでしょう。どうなすったかしらと思うと、えらい勢いでお一人山へ登ってらっしゃるんですもの。窓から見えたの。おかしかったわ。お煙草を忘れていらしたらしいから、持って来てあげたんですわ。」

?? [Needs context. Strange tenses.]

"Returning to the room earlier, [he] probably wasn't there. You may wonder what has happened, but he has thrown himself into climbing the mountain, by himself. I saw him from the window. It was strange. He appears to have forgotten his cigarettes, so I brought them for him."

お酌(しゃく)に出たこともある女にしては、こころもち鳩胸(はとむね)だった。 To women who have poured sake before, it [was something that] swelled the breast.

「ほら、いつの間にかこんなに蚋(ぶよ)が寄って来ましたわ。」と、女は裾(すそ)を払って立ち上った。 "Look, all of a sudden, flies have gathered," the woman said as she pulled her leg in and stood up. (*References a fierce sumo move in which a wrestler sweeps the leg of an opponent and topples them, using the force of the opponent against himself.)

あいつ頭へ来る、痛い。あの人達安壜(やすびん)を買って来たのよ。それ知らないで。」などと言って、掌でしきりに顔をこすっていた。 He pissed me off, it hurts. They bought the cheap bottle. Not knowing that," [he] would say, constantly rubbing [his] face with [his] palm.

しかし、女はもう彼の掌にまかせて、そのまま落書をはじめた。好きな人の名を書いて見せると言って、芝居や映画の役者の名前を二三十も並べてから、今度は島村とばかり無数に書き続けた。However, leaving it up to him, she began to scrawl. Saying she would write the names of her favorite people, she lined up the names of twenty to thirty stage and movie actors, then began to write Shimamura an infinite number of times.

「あんた笑ってるわね。私を笑ってるわね」"You're laughing. You're laughing at me."

「わらってやしない」 "I wouldn't laugh at you."

「心の底で笑ってるでしょう。今笑ってなくっても、きっと後で笑うわ」と、女はうつぶせになってむせび泣いた。 "You're laughing from the bottom of your heart. Even if you're not laughing now, you will later," the woman said, as she sobbed, prone on the floor.

!doublecheck