I am not sure what your point is here. We appear to agree that only Jews were under the "ceremonial" parts of the Law. As you probably know I do not see any Biblical basis for carving the Law of Moses up into a "ceremonial" part and "moral" part - this strikes me as an artificial division that you (and many others) have imposed.
It's only 'artificial' to an Israelite. Because, like I said, they are the ones who were accountable to all aspects of Mosaic law, ceremonial and moral. They are the one's who agreed to the first covenant in the complete package of law that it was. They didn't agree to just part of it:
“We will do everything the LORD has said.” (Exodus 19:8 NIV1984)
Yes, I "get" this notion that some elements of the law appear to be "purely moral" and other parts appear to be purely "ceremonial". But, and this is key, you need to make an actual case that the moral parts of the Law of Moses were "written on the hearts of the Gentiles".
You have already done that for us when you said that you would 'not deny that all human beings are "aware" of the moral "law" of God.' Paul plainly says it anyway right there in Romans 2...
"...when Gentiles, who do not have the law, do by nature things required by the law, they are a law for themselves, even though they do not have the law, 15 since they show that the requirements of the law are written on their hearts" (Romans 2: NIV1984)
Trust me - I fully believe, not least because of Paul's argument in the last half of Romans 1, that all humans are aware of the moral imperative to not murder, to not commit adultery. And this is where semantics come in.
They are accountable to, and under, whatever part of the law of Moses is
"written on their hearts" (Romans 2:15 NIV1984), thus making the
"whole world...accountable to God" (Romans 3:19 NIV1984).
You appear to think that this means that Gentile are "under" the moral part of the Law of Moses.
Well, I doubt it. Let me try an analogy. I am a Canadian. Let's assume you are an American (given your "nickname" of Jethro Bodine, I assume this is a safe bet). Here is the argument:
1. American law prohibits murder;
2. As a Canadian, I am not under American law - if I choose to murder 100 of my fellow Canadians, I have not, in any sense, violated American law;
3. Am I under God's "general worldwide moral imperative" to not commit murder? Of course!
Do you see the point? A Gentile who commits murder somewhere in Timbuctoo is not under the Law of Moses in respect to its prohibition against murder. But that doesn't mean that God does not have a "moral law" that reflects some of the same things that the Law of Moses embodies, and that is "known" by all people. I suggest this is a better way to see things than to make what I think is the Biblically unsupported position that "part" of the Law of Moses is known to Gentiles. Remember - it is a written code.
A more accurate and applicable analogy would have the two separate jurisdictions under one larger authority. The closest analogy that I can think of would be the United States and one of it's territories, like American Somoa.
It's not a perfect analogy, but you can see how in that analogy there is one supreme authority that both, citizens in the United States itself, and citizens in Somoa share accountability to
certain aspects of the same law and enforcer of that law, just as I'm arguing that Israelites and Gentiles did to the law of Moses and God. Canada and the United States do not have that kind of relationship with each other. They are completely sovereign. It's not a good analogy to illustrate how God rules over all the nations and peoples of the world, but who live under different aspects of law under his one rule.
And while we're at this, on precisely what basis do you determine that an element of the Law of Moses is "moral" and which is "ceremonial"?
Moral laws govern how we relate to, and treat one another, summarized in the command,
"love your neighbor as yourself" (Lev. 19:18 NIV1984). Ceremonial laws govern how we are to approach God in worship. The ceremonial laws include all the worship, cleanliness, and separation laws. Violating any of these made you unfit to approach God. Those were binding stipulations of a previous and different covenant, the first covenant.
But now a New Covenant is in place that brings us near to God through faith in Christ, making the old regulations of how and when and where to approach God obsolete (no longer needed or applicable). For example, what law of who, and when, and where, and how a person can approach God behind the curtain applies to a person
who has already entered in through the blood of Christ? What application does that law have to a person who is already legitimately behind the curtain and ministering to God through the blood of Christ? So it's easy to see how the ceremonial law is indeed very much obsolete and no longer binding on the people of God. But who would dare say we are now free to murder another person because of our faith in Jesus Christ?
The law about observing the Sabbath is in the 10 commandments.
Is this a universal moral law "written on the hearts" of all men?
I personally don't believe so. It's interesting that it finds it's true spiritual fulfillment when you "love your neighbor as yourself". Isaiah 58 gives us insight into how taking a good long rest from beating up on each other and speaking ill words of one another is the Sabbath (and fast) that God has chosen for his people and which pleases him.
To help us further understand the seemingly ceremonial aspects of the first Four Commandments versus the relational and moral aspects of the remaining Six, and how those first Four also find their fulfillment when we love others through our faith in Christ's forgiveness, Paul says that
"whatever belongs to your earthly nature: sexual immorality, impurity, lust, evil desires and greed, ...is idolatry". (Colossians 3:5 NIV1984) See? When we transgress these relational/moral issues Paul is saying
we are actually guilty of idolatry and have broken the 2nd Commandment
which most people see as a purely ceremonial type of law.