The problem was not that 'some Jews were not putting their faith in Christ'.
The problem was that some Jewish Christians were obliging the Gentile Christians to observe the Law.
They were Judaisers, 'the party of the circumcision', those who said 'except ye be circumcised after the manner of Moses, ye cannot be saved', and they, 'by good words and fair speeches' were causing divisions and deceiving the hearts of the simple.
 
The problem was not that Christ was being rejected by them, but that they insisted that both Christ AND the Law were necessary for salvation.
 
The fact is that (for a Gentile) observing the Law is not significant to salvation.
 
It is incumbent upon a Jew (Christian or not) to observe the Law, no such obligation is laid on the Gentiles.
God does treat individuals differently, one from another (think on David, his adultery with Bathsheba and his murder of Uriah, or Naaman the Aramite Captain, his dispensation to enter an idolatrous temple, or others) and also Jews are treated differently to Gentiles (the Jew FIRST, and also the Gentile, is the constant refrain).
 
Of all the Gentiles with whom Jesus had dealings not one was told to observe the Law.
Jesus' only concern was with their faith, not their standing in the Law of Moses; but when he spoke with Jews it was a very different matter, a Jew had to have faith AND be observant of the Law.
 
Paul had much more to do with the Gentiles than Jesus.
Much of Romans, Galatians and Colossians is concerned with examining the differences between Jewish and Gentile Christians and three chapters of Acts could be added to the list.
Paul fought, with every breath, against the idea that a Gentile should observe the Law and he paid heavily for his stand. Not once did he back down, not even from Peter or James.
He was so rock solid on this because he recognised the danger from the self-satisfaction and self-righteousness that a 'shew of wisdom in will worship, and humility, and neglecting of the body' can generate in the mind of the flesh.
 
If what I (and others) have said makes no sense to you, then stop and think about it, because what has been said has mostly just quoted Paul, the Apostle to the Gentiles.
When he spoke to Jews he upheld the Law, because the Law is essential to a Jew's salvation.
When he spoke to Gentiles he required nothing more from them than was necessary for fellowship with the Jewish Christians because Gentile salvation is without the Law.
 
Our viewpoints do differ on the Law.
I have the advantage of having been where you are now, or so it seems to me.
I came to Christ through the OT; the NT had little appeal, didn't make much sense, to me until I had a grounding in the OT; and I struggled long with the notion of doing the Law as a non-Jew.
So I have an empathy, not merely a sympathy, for the things that you say and seek to do.
I can even see that some advantages (in understanding the 'why') accrued to me from my mis-guided endeavour; but, I have come to agree entirely with Paul on this and think myself most unlikely to change back to my previous thinking. He makes his case far too well.
 
Christ did not completly destroy the Law.
For Jews (whether Christian or not) the Law is as significant as it was in the 1st century.
The ordinances of the Law that kept Gentiles from approaching near to the Holy place were completely destroyed. We can all enter in with Christ.
The sacrifices for sin were completely destroyed. There is no more a sacrifice for sin, save the sacrifices of our lips and the sacrifice of tears.
The traditions that grew out of the Law were completely destroyed. If they ever carried the significance that men attach to such things.
I don't think much else passed away, maybe someone can help me out a little (or a lot) here.
 
In Leviticus 1.2 God says to Moses 'Speak unto the children of Israel, and say unto them, If any man bring an offering .....' and He proceeds to define, by a series of commands, what is an acceptable offering and the manner in which it is to be offered.
First point being, the commandments (of the Law) are specifically directed to the children of Israel, not to Gentiles.
Second point, God defines what is an acceptable expression of worship, not man.
It appears to me that a Gentile intruding his/her worship into that private arrangement (covenant) between God and Israel is like someone taking a seat at a higher table at the feast than has been apportioned to him/her.
It is not the form of acceptable worship that God has commanded for Gentiles.
 
Jesus repeats 9 of the 10 Commandments and adds others, John adds 1 and with Paul et al many more are added by strong implication and example. Try a google of the 'Commandments of Christ' and see for yourself.
My interest is more inclined to keeping the New Covenant than the Old (and essentially private) Covenant between God and Israel.
 
I don't think that eating dogs or cats (or anything other than blood and things sacrificed to idols) is excluded to a Gentile. Though you would be hardpressed to get me to eat either, and may I never be so hungry as to consider it. OTOH, it might just be a matter of the right sauce.
You may note that the OT dietary laws do not say that the food is detestable to God.
Eating the food makes only an Israelite (someone under the Law) unclean.
Not eating it is a sign of Israel's Covenant with God, and that Covenant is not so easily entered into.
 
You say things like 'it shows God that I really do care' , 'it will please God' and other such things, but do not see that same thinking is exactly what Paul warns against when opposing the keeping of the Law by Gentiles.
You can't show God anything; and your not eating a crab salad does not please Him, it is not His will for you as a Gentile.