Hi Yousef, Since it's a metaphor you could interpret it very differently. It means that a man was looking at another person and the latter could tell there was something meschivious or evil in his look. "The laughter was shining dark": something can not shine dark, it's a contradition, that's why is figurative, you shouldn't take it literally, but it makes you think there's something misterious or even wicked with that man.

No problem! It means "at that moment", in the past, the speaker thinks a woman is living with a movie producer because in the past she was planning on living with an artist, so he thinks it's the same person. "was then" means she was living with a movie producer in the past. Hope it helps!

Laughter shining dark from his eyes, implies dark laughter coming from his eyes, or that he is probably leering at you.