There is nothing sinful about not following laws that we legitimately can't keep and that should not prevent us from getting to experience obedience to the laws that we can legitimately keep. For example, in Deuteronomy 17:18, it specifically instructs the king to write a copy of the Torah, so only the king can get to legitimately experience obedience to that law and everyone who is not the king has a legitimate reason for not following it. Not even Jesus got to experience obedience to the laws in regard to giving birth or to having a period, but again there is nothing wrong with that. The Israelites were give a number of laws that had the condition "when you enter the land" while they were still wandering the wilderness for 40 years that a generation did not get to keep, but that did not prevent them from getting to keep them as soon as they entered the land. The condition for the Israelites to return to the land after they had been exiled to Babylon was to return to obedience to the Torah, which contains instructions in regard to Temple practice which they could not obey while they were in exile, so that did not prevent them from getting to obey the laws that they could obey.
God's character traits are eternal, so there is a reality of what is true about who God is that we true before He gave any laws, that has been revealed through His laws, and that is true regardless of which covenant someone is under if any. For example, God's righteousness is eternal (Psalm 119:142), therefore all of His righteous laws are eternal (Psalm 119:160), so anyone who has the goal of embodying God's righteousness will consider any instructions that He has given for how to do that to be eternally and cumulatively valid. It is not the case that that someone were have no obligation to embody God's righteousness if they were not in a covenant relationship with Him, so it is missing the point to focus on the specifics of God's covenants instead of on what they teach us that is eternally true about who God is.
The Hebrew word "Torah" used in Jeremiah 31:33 refers to all of the Law of Moses, not to just the Decalogue. In Deuteronomy 30, it forms the basis for the New Covenant by prophesying about a time when the Israelites would return from exile, God would circumcise their hearts, and they would return to obedience to the Torah, which is what Jeremiah 31:33 and Ezekiel 36:26-27 are in regard to. In Ezekiel 36:26-27, God will take away our hearts of stone, give us hearts of flesh, and send His Spirit to lead us to obey the "mishpatim" and the "chukim, which again are not limited to just the Decalogue but are the two main categories of law in the Law of Moses.
The phrase "the Law and the Prophets" is like saying "the Gospels and the Epistles" and refers to everything within a large body of text, not to just the Decalogue.
While it is possible to interpret Acts 15:19-21 as ruling against followers of Christ following over 99% (609/613) of what he taught, I don't think that it makes much sense to do that. Do you think that Acts 15:19-21 contains an exhaustive list for mature believers? It is would be contradictory to treat it as being an exhaustive list for mature believers in order to limit which ways Gentile followers of Christ should follow Christ while also treating it as being a non-exhaustive list by taking the position that there are obviously other ways that followers of Christ should follow Christ, such as with the greatest two commandments, the Decalogue, or those things spoken against in Romans 1:29-31, 1 Corinthians 6:9-11, and Galatians 5:19-21, or Titus 3:1-3. Moreover, the the reason why the commandments to love God and our neighbor are the greatest two commandments is because they are inclusive of all of the other commandments, so the moment that you include those you also include everything else in the Law of Moses.
Is God's holiness eternal or did it fail to get renewed under the New Covenant? In 1 Peter 1:16, we are told to be holy for God is holy, which is a quote from Leviticus where God was giving instructions for how to do that, such as by refraining from eating unclean animals (Leviticus 11:44-45) or by following "ceremonial or boundary-marker provisions". If our goal is to embody God's character traits, then the only way that we should cease to follow God's instructions for how to be holy as He is holy would be if He were to cease to be holy under the New Covenant. Morality is based on God's character traits, which means that God's instructions for how to be holy as He is holy are moral laws as well as everything else in the Law of Moses, so none of it has been set aside.