It is hard to differentiate between Yahweh's laws and mans' laws. But the Bible clearly defines the royal law versus the handwriting of ordinances against us.
I am not sure what handwriting of ordinances means to you. But to me it means the charges written in Greek, Latin and Hebrew as found here.
Lu 23:38 And a superscription also was written over him in letters of Greek, and Latin, and Hebrew, THIS IS THE KING OF THE JEWS.
Joh 19:20 This title then read many of the Jews: for the place where Jesus was crucified was nigh to the city: and it was written in Hebrew, and Greek, and Latin.
In more simple terms, it is referring to the Ten Commandments and the Law of Moses. "If ye love me, keep my commandments." John 14:15. In other words, the Ten Commandments are about loving Yahweh and loving your neighbor. James 2:8, 1 John 3:3-4 Keeping the Ten Commandments brings blessings to those that choose to observe them.
It seems you are saying the law of Moses is not God's law? But, It is not clear.
Whereas the Mosaic law is about ceremonial laws that also include a advice on how one should eat. The Mosaic law is mostly applicable to the House of Judah and to the House of Israel, whoever these people may be, but I am not sure that it is applicable to all groups of people. But I do keep in mind that the scripture does prophesy about a return to the Mosaic law. Mal 4:4-6. If one is in a position to fully observe the Law of Moses than they should do so and help others to do so. But your life is more important to Yahweh than strict observance of the Mosaic law.
Advice on how to eat? It was God's law given to Israel by the hand of Moses was it not?
This is the way that I look at Yahweh's laws versus Mans' laws that says, you have to observe this day in this manner or you are sinning.
God seemed pretty serious about what He commanded.
Lev 17:1 And the LORD spake unto Moses, saying,
2 Speak unto Aaron, and unto his sons, and unto all the children of Israel, and say unto them; This is the thing which the LORD hath commanded, saying,
3 What man soever there be of the house of Israel, that killeth an ox, or lamb, or goat, in the camp, or that killeth it out of the camp,
4 And bringeth it not unto the door of the tabernacle of the congregation, to offer an offering unto the LORD before the tabernacle of the LORD; blood shall be imputed unto that man; he hath shed blood; and that man shall be cut off from among his people:
5 To the end that the children of Israel may bring their sacrifices, which they offer in the open field, even that they may bring them unto the LORD, unto the door of the tabernacle of the congregation, unto the priest, and offer them for peace offerings unto the LORD.
6 And the priest shall sprinkle the blood upon the altar of the LORD at the door of the tabernacle of the congregation, and burn the fat for a sweet savour unto the LORD.
7 And
they shall no more offer their sacrifices unto devils, after whom they have gone a whoring. This shall be a statute for ever unto them throughout their generations.
8 And thou shalt say unto them, Whatsoever man there be of the house of Israel, or of the strangers which sojourn among you, that offereth a burnt offering or sacrifice,
9 And
bringeth it not unto the door of the tabernacle of the congregation, to offer it unto the LORD; even that man shall be cut off from among his people.
10 And whatsoever man there be of the house of Israel, or of the strangers that sojourn among you, that eateth any manner of blood; I will even set my face against that soul that eateth blood, and will cut him off from among his people.