And you don't understand the gospel if you think turning students in is always the best course of action. Your brand of gospel is one that seems to coincide well with the "Javerts" of the world.
Your sister sounds like she was in some serious stuff, I think there is a clear difference between that and being in the room with a member of the opposite sex and studying or any number of things an over zealous self-righteous person would love to turn someone in for.
What you describe is the opposite of the gospel and one foreign to any description of Jesus. Did Jesus have the adulterer stoned as was legal and lawful or did he condemn them all and show love to her. He didn't enable it but he empowered her to walk away having repented. Yes, repentance is not a transaction with The Lord but a fresh view of the world (read the bible dictionary).
BYU is would add pharaseeical studies as a major... Thank goodness the real world isn't like byu in this regard.