Customers who come just as the store is about to close are quite troublesome.
I wish they would come to the store when there is still enough time left before closing.
ご質問ありがとうございます。
"Customers who come just as the store is about to close are quite troublesome."=「お店が閉まる直前に来る客はかなり面倒です。」
"I wish they would come to the store"=「彼らが店に来ればいいです」
"when there is still enough time left before closing."=「まだ閉まる前、十分に時間があるときに。」
ご参考までに。
Customers who rush into our store just before we close are really annoying.
Customers who stampede into our shop at closing time are really irritating.
この場合、次のような言い方ができますよ。
ーCustomers who rush into our store just before we close are really annoying.
「閉店間際に駆け込んでくる客はすごく迷惑」
to rush into ... で「…に駆け込む」
この場合の「迷惑」は annoying を使って表現すると自然な感じで良いでしょう。
ーCustomers who stampede into our shop at closing time are really irritating.
「閉店時間に店に駆け込んでくる客はすごいイラつく」
to stampede into ... で「…に駆け込む」とも言えます。
annoying の代わりに irritating を使っても言えます。
「余裕を持ってきてほしい」は次のように言うと自然な感じで良いと思います。
ーI wish they would come a little bit earlier.
「もう少し早く来てくれるといいのに」
ご参考まで!