I see that you have not addressed the Ten Commandments issue. Might I be so bold as to hope that you have abandoned this specious line of argumentation?
Concerning the Sabbath, the Catholic Church never changed the time of the Sabbath. According to the law, the Sabbath is on Saturday. I state this as a matter of fact.
We worship on Sunday as a Sabbath to Our Lord as a commemoration of His Resurrection. According to Saint Augustine, “We are a people of the Resurrection.” Similarily, on Friday we remember the Lord’s Passion by mortifying the flesh and undertaking acts of penance and fasting.
No times have been changed. The Sabbath of the law is still on Saturday. We just don’t hold anyone to observation of the old law Sabbath, just as we recognize that the Messiah loosed most of the mitzvot of the Torah.
If someone wishes to observe the law then they may as long as they do not believe that their salvation comes from the works of the law.