Weird Family Relations and Ruthless Opportunism Rewarded in Genesis

Never mind Lot being made drunk and seduced by his daughters - what's with all this pretending that your wife is your sister?  We know that Abraham and Sarah are first cousins, as are Isaac and Rebecca. Jacob, Leah and Rachel are first cousins, as are Esau and his wife Mahalath (Ishmael's daughter). That's a little unsavory to the Western mind, but completely normal in Semitic, and modern Arab culture.  In Slavic culture first cousins are also called sisters and brothers.  This story of pretending that the sister is the wife has occurred three times so far - twice with Abraham and Sarah, and now once with Isaac and Rebecca.  Are these guys cowards? Or are the locals so barbaric that they would indeed kill the husband to get the wife?  In each case the locals turn out to be not so barbaric, but so traditional and superstitious that they express moral outrage upon finding out that the couple is really husband and wife.  Strange.

The episode of Jacob and Rebecca conniving against Isaac and Esau is pretty unsettling too.  This is the behavior of patriarchs and matriarchs to be admired? Deliberately lying and cheating because you feel entitled to a "blessing" which says that others should serve you?  I fail to see anything positive or redeeming in Jacob/Israel.  He's the prototype of the ruthless opportunist who is willing to stab in the back those close to him so that he can get ahead.  He behaves like a walrus or gorilla, not an evolved human.  (Genesis 27)

Rebecca's kvetching about her Hittite daughters-in-law is pretty amusing.  Gen.27:46: "And Rebekah said to Isaac, “I am weary of my life because of the daughters of Heth; if Jacob takes a wife of the daughters of Heth, like these who are the daughters of the land, what good will my life be to me?”