Which commandment is "wrong"? You don't seem to understand that God didn't give us a whimsical list of arbitrary hoops to jump thru, it's "liberal" politicians, some school teachers, some religionists and other people controllers who do that! God simply gives us the best list of things we can measure our own lives and hearts against.
You seem to want to measure other men against a "sin" list of your own making and, in that, you duplicate the errors of the pharisees of Jesus' day; that's bad spiritual juju my friend.
Bottom line, making judgement of God's instructions is way above my pay grade. Unlike your RCC priest's and their traditions, I don't make distinctions about large or small sins because I know God judges men's heart because that's what leads to sinful acts! The rules/Commandments of God that you don't like simply tell us the standards we should all be living by.
Contrary to (what I know of) RCC teachings, if we follow the "Church's" rules perfectly but do it without a right heart we'll get nothing spiritual. (See Jer 17:9-10; Mk 7:21-22)
As to which Commandment is "wrong", I'm not touching it; you're a trained catechism teacher and I'm not so you'll have to make that judgement yourself. But be careful .... !!