How does the line "But soft, what light through yonder window breaks?" (2.2.2) propel the motif of light and dark imagery in Romeo and Juliet?

By comparing Juliet to the Moon, and still being more beautiful, what allusion is Romeo making? To _____ in Greek Mythology.

"The brightness of her cheek would shame those stars/ as daylight doth a lamp" (2.2.19-20). What literary element is this?

In "Wherefore art thou Romeo?" (2.2.36) what does "wherefore" mean?

"At lovers' perjuries, they say Jove laughs." (2.2.97-98). What allusion is being made? Why would Jove laugh?