Rev 3:9: “Indeed I will make those of the synagogue of Satan, who say they are Jews and are not, but lie—indeed I will make them come and worship before your feet, and to know that I have loved you.”
From Jesus own Words He did not abolish the moral laws which the Holy Spirit writes on our hearts (as you have pointed out). I know you are not advocating that (abolishing the moral laws), there are only fringe antinomians (still among us today) who do that.
You were correct that in many ways we are talking past each other.
Point in case is thinking those who love to study and understand the Torah are trying to bring legalism and works to saved by Grace through faith. I don't see it like that at all. For me, once saved by God's Grace no works I do or anyone other human can do will "earn" them salvation. Once saved by Grace there is 'work' to do as a child of God who cries "Abba Father." It is not works for salvation or to keep it etc. It is the work we were fashioned to do when becoming new creatures:
Luke 2:
“The harvest is plentiful, but the laborers are few; therefore beseech the Lord of the harvest to send out laborers into His harvest. 3 Go; behold, I send you out as lambs in the midst of wolves.
At a bare minimum we are charged to be seed sowers and share the Gospel.
The second point I would like to make is we who are saved by God's Grace have become a new creature. We become followers of Jesus Christ. He is our Lord and Savior. As our Lord we do what He tells us to do and obey His Words. Doing so is not works based salvation. We love Him so we as His bond-servants want to emulate Him, please Him and the best way to do that is to keep those things He said He wanted His disciples to do. That is not works based salvation. At the very least it is honoring Him.
A way to look at it is the saved pound dog. The pound dog is saved from the dog catcher's needle of death by someone who pays for them and adopts them. When that pound dog goes home with his owner they turn out to be the most thankful and obedient pets in the world. They somehow 'know' that if it was not for the owner paying for them and adopting them, they would be dead. Well that is my stab at a similtude that will most likely get taken out of context:)
So for me when someone says "study the Torah" AND most importantly study the Actual Words of Christ in the Gospels and elsewhere: that means to me Jesus Christ, who I have confessed with my mouth and believed in my heart as my Lord and Savior tells us how He wants us to be in our relationship with Him and fellow believers and mankind. That is not legalism unless I replace my liberty given in Grace for a man-made understanding of self-sanctification and also if I try to project and require it on others. That is the Synagoge of Satan right there.
But striving to be the best foot soldier for my General Jesus Christ by following His orders is not legalism. A good soldier must know the field manuals to be an effective and productive soldier. Again, not legalism it is loving my Master and Savior who I know did it all, paid the full price, went the full distance and cried out "IT IS FINISHED."
Ephesians 2:10
King James Version (KJV)
10 For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them.