I respect your viewpoint on that but I don't interpret Sacred Scripture such that the ten commandments are binding on Christians as a legalistic code to be rigidly applied.
In Matthew 4:15-23, Christ began his ministry with the Gospel message to repent for the Kingdom of God is at hand, which was a light to the Gentiles, and God's law was how his audience knew what sin is (Romans 3:20), so repenting from our disobedience to it is a central part of the Gospel of Christ, which includes repenting from breaking the Sabbath. Furthermore, Christ set a sinless example of how to walk in obedience to God's law, including keeping the 7th day holy, and we are told to follow his example (1 Peter 2:21-22) and that those who are in Christ are obligated to walk in the same way he walked. So Christ spent his ministry teaching his followers to obey God's law by word and by example and being a Christian is about following what Christ taught.
I interpret Sacred Scripture such that the moral precepts of the ten commandments are binding on Christians, but the law is not to be applied as a strict legalistic code as it was in the Old Testament.
The Bible often uses the same terms to describe aspects of the nature of God as it does to describe aspects of the nature of God's law, such as with it being holy, righteous, and good (Romans 7:12), or with justice, mercy, and faithfulness being weightier matters of the law (Matthew 23:23), which is because it is God's instructions for how to testify about those aspects of His nature, and aspects of His nature are the moral precepts. For instance, our good works testify about God's goodness, which is why they bring glory to Him (Matthew 7:23). Likewise, in 1 Peter 1:16, we are told to be holy for God is holy, which is quote from Leviticus where God was giving instructions for how to do that, which includes keeping God's Sabbaths holy (Leviticus 19:2-3), so by following those instructions we are testifying about God's holiness, and by not following those instructions we are testifying that God is not holy.
God could give someone a list of 100 instruction how to testify about His goodness in various situations, which would allow them to extrapolate are moral principle of goodness that all of those instructions have in common, which would lead them to take actions that are examples that moral principle in accordance with those 100 instructions, even in situations that are not part of that list. Correctly understanding the moral principle of goodness will never lead us away from taking actions that are examples of that principle that were part of that list. Someone would be missing the point if they thought that they correctly understood the moral precept of love, so they no longer needed to take actions that are examples of it. Likewise, the Ten Commandments are examples of moral precepts, so you would be missing the point if you do not consider those moral precepts to be inclusive of the Ten Commandments.
The specific day is a more of a ceremonial aspect of the commandment in my view, and the moral precept is that we have a duty to set aside a set time to give God the proper worship that he is worthy of.
There is nothing about some of God's commands having ceremonial aspects that means that we can be acting morally while disobeying those commands. Morality is in regard to what ought to be done and we ought to obey God, so all of God's laws are inherently moral laws. Legislators give laws according to what they think ought to be done, so for you to suggest that there are aspects of God's law that are not moral aspects is to claim that God made a moral error about what ought to be done when He commanded those aspects, which is claiming to have greater moral knowledge than God.
God commanded to keep the 7th day holy, so we can either lean on our own understanding by doing something else or we can trust God with all of our heart by keeping the 7th day holy and He will make our way straight.
And I interpret Scripture and Sacred Tradition such that the apostles had the authority to move the particular day of worship, and that they did change it.
What do you think is the extent of this authority? For example, did Peter have the authority to change God's command against murder into a command to commit murder? In Deuteronomy 13:1-5, the way that God instructed His people to determine that someone is a false prophet who is not speaking for him was if they taught against obeying God's law. So when God commanded to keep the 7th day holy and someone says that we shouldn't obey what God has commanded and should do something else instead, then by considering that person to be a false prophet we would be correctly acting in accordance with what God has instructed His people to do.
