Didn’t Jacob only recieve his father blessing through deception?
Didn’t Jacob screw over his father in law?
Wasn’t Jacob a polygamist?

Yes, yes, and yes.
Esau forfeit his inheritance.
He should have been in the Christ line, and purposely took himself out of it.
Esau married outside the Semites, therefore Leah had no husband and Laban tricked Jacob into marrying her first, before Rachel.
In summary,
Esau didn't want to do God's will but still wanted the blessing, which he had carelessly sold off to Jacob.
Then Laban deceived Jacob into marrying his older daughter, that Esau by rite of consanguinal marriage, should have married.
Jacob kept the bloodline of Shem intact, and Jesus came down genetically through his son Judah.
Remember what Laban told Jacob when Jacob got pissed he was trivked to marrying Leah instead of Rachel?
Laban told him it is customary to marry off the oldest daughter first. She was supposed to be Esau's.