The author of this story is unknown.
This milk doesn't have an expiration date on it.
Huh? When you were sleeping you used an onion for a pillow? I don’t really get what you’re saying.
Something that is not bright is cloudy and fuzzy. What do you think when you look into the fuzzy clouds? It is the unknown, the unclear, the uncertain.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.