I would say.. ~하기는 한거야? Did you even study for your exam the other day? 너 그 날 (the other day) 시험공부 하기는 한거야? Did you even eat your food? 너 음식 먹기는 한거야?

Not a grammar expert but hope it helps! 기대 : hope, expectation 나 : or 헛된 기대 (나) : false hope (or)

Is this only available in South Korea? : (이 상품을-This product) 한국에서만 살 수 있나요? Is it or can it be available for the U.S? : (이 상품을) 미국에서도 살 수 있나요? Hope it helps and you can get the merch!

at first i thought it means a war without reason but after reading the next sentence, Kim's guess sounds right !

There is only one typo! 제가 지금 발표하는 이분들도 이 도전에 첫발을 < 내딛으신 >분들인데요. 설레임과 성취감으로 앞으로 가득차 실 분들입니다. You got all well👍

The people I'm going to introduce to you right now are those who have taken the first step in this challenge and are filled with excitement and accomplishment.