These are all very interesting passages and ones that I have attempted to study and discern at some length. There are a couple of things that caused me to hit a dead end with my studies with this system.
1). There is not a good correlation with the solar cycle. I realize that by the time they came back from Babylon that this appears to be the primary way that their sabbaths were observed. However, this system meshes the lunar with the solar cycles atrociously as it is only corrected every 3 to 4 years or 7 times in the course of 19 years. In my opinion, this is a very sloppy system although obviously in use after the Diaspora. I realize that there are given explanations for this, however, all of them that I've seen seem to have uninspired human intervention at the source.
2) It fails to recognize or reconcile with other less popular observances of sabbaths (post Babylon such as is mentioned in Dead Sea Scrolls) even though these other less popular systems have a much more reliable provenance being kept by the group that had come out from among the idolatrous Israelites apparently as early as Isaiah's time and using as the source for their observance the Book of Enoch and the tables which do appear to reconcile the lunar with the solar cycles much better.
3)The writers of the New Testament characterized such observance as having something to do with worshipping beguiling angels in contrast to YHWH as in Colossians 2:17 & 18 This is also borne out in much greater detail once you begin to study early christian apologists (no later than mid 2nd century) who were witnessing to practicing Jews who still observed using this system. Without exception, all of them that I have found regarded this system as worshipping angels. And this is at least 200 years-ish before the unholy alliance between pseudo-christianity and paganism.
Colossians 2:18
Let no man beguile you of your reward in a voluntary humility and worshipping of angels, intruding into those things which he hath not seen, vainly puffed up by his fleshly mind,
And not holding the Head, from which all the body by joints and bands having nourishment ministered, and knit together, increaseth with the increase of God.
I can appreciate that for your family you are trying to follow truth as you have found it, however at this point, for me, there are too many unsolved discrepancies for me to seriously consider this system.
Peace
1). There is not a good correlation with the solar cycle. I realize that by the time they came back from Babylon that this appears to be the primary way that their sabbaths were observed. However, this system meshes the lunar with the solar cycles atrociously as it is only corrected every 3 to 4 years or 7 times in the course of 19 years. In my opinion, this is a very sloppy system although obviously in use after the Diaspora. I realize that there are given explanations for this, however, all of them that I've seen seem to have uninspired human intervention at the source.
2) It fails to recognize or reconcile with other less popular observances of sabbaths (post Babylon such as is mentioned in Dead Sea Scrolls) even though these other less popular systems have a much more reliable provenance being kept by the group that had come out from among the idolatrous Israelites apparently as early as Isaiah's time and using as the source for their observance the Book of Enoch and the tables which do appear to reconcile the lunar with the solar cycles much better.
3)The writers of the New Testament characterized such observance as having something to do with worshipping beguiling angels in contrast to YHWH as in Colossians 2:17 & 18 This is also borne out in much greater detail once you begin to study early christian apologists (no later than mid 2nd century) who were witnessing to practicing Jews who still observed using this system. Without exception, all of them that I have found regarded this system as worshipping angels. And this is at least 200 years-ish before the unholy alliance between pseudo-christianity and paganism.
Colossians 2:18
Let no man beguile you of your reward in a voluntary humility and worshipping of angels, intruding into those things which he hath not seen, vainly puffed up by his fleshly mind,
And not holding the Head, from which all the body by joints and bands having nourishment ministered, and knit together, increaseth with the increase of God.
I can appreciate that for your family you are trying to follow truth as you have found it, however at this point, for me, there are too many unsolved discrepancies for me to seriously consider this system.
Peace