What was the consequence of their crying?
Torah Temimah citing Sotah 42b: In the merit of four tears that Orpah shed for her mother-in-law, she merited to bear four mighty men - "they cried more." Rashi (42b) - she cried twice. Presumably, each time a tear came from each eye.
Why did Orpah kiss Na'ami?
Malbim: It was kissing of one who leaves [his beloved]. Orpah intended only for what is beneficial [and Na'ami explained that there is no benefit to return with her].
What is the significance of Rus clinging to her?
Torah Temimah citing Sotah 42b: "These four were born to Harafah in Gas, and fell to David and his servants." The sons of the one who kissed will fall to the sons of the one who clung.
Malbim: Rus intended for what is good.
