The rights of the first born included things like headship of the tribe or family and a double portion of the inheritance. But it was a common practice for a father to give that right to the firstborn of the wife he loved more. Joseph happened to be the former. His brothers resented that because Joseph was number 11 in line. But if you read about his brothers they forfeited their inheritance rights by their own actions. Reuben committed incest. Simeon and Levi committed murder. And in short, the rest plotted against Joseph which showed their hearts were not what God wanted to use. For the time being Joseph would be the deliverer of his people.
We also read that Jacob is the man of God who is ready to be used. The final sign of this was the changing of his name to Israel. The word "Israel" means "protected by God". This was a covenant. The name change is a permanent sign by God. Jacob will no longer try and make a deal with God. he knows he will be protected. There are no more ifs.
Joseph probably had the most to complain about more than any other character in the Bible, possibly enough to even be compared to Job. But he never lost his focus. He never lost his relationship with God. And that is odd knowing how wishy-washy his father was with the relationship with God. Somehow Jacob must have installed Abraham's and Isaac's beliefs on him. God never forgot about Joseph either. He made him prosper even in the "pit" of his life. If we hold on to this truth, Never will I leave you, then life can be what we want it to be. The problem is we don't acknowledge God in many situations except the hardships. He is knocking on the door but it is up to us to let him in.
After 22 years of separation and a lot of time to let his anger burn against his brothers, we never hear of such an emotion coming from Joseph. Even when he had the opportunity to get revenge, his compassion showed in the end. Many time we can't do that. His brothers tried to kill him and he forgave them. but we can't even forgive if someone says one harsh word that doesn't even mean anything in the end.
To forgive is divine, but it should also be human.