So you see the capital-L "Law" as something apart from Torah, and "torah-observance" as "a" way a person can come to "understand" the "Law"? What then do you mean by "Law"? And how do those of us who are not 'observing torah' come to "understand" it?
I'll come back to labels later. More interested in defining terms first.
Law and law, Torah and torah, are all the same to me, its the whole Word of God. However I do understand that others differentiate the two, torah/law being the complete Word of God and Torah/Law as the first five books of the bible. And a 'torah-observant' person would be one that tries to fulfill the commandments established with those five books. Again just what I think, I am not one who observes torah specifically, but yet understands that the commandments have a purpose in our lives, but my focus is more on the spiritual side. Most torah-observant people try and uphold the Laws stated in the five books, however there are other Laws that don't seem to get the same generated interest. For instance, Luke 22:19 And he took bread, gave thanks and broke it, and gave it to them, saying, "This is my body given for you; do this in remembrance of me.", this is a New Covenant direct command, but no one really spends any energy trying to figure out how to do this. Which is odd to me, because there is whole religion based on observing the old covenant commands but few pay attention to the ones in the new.
Law to me is the Word of God, everything that helps me understand the way God wants me to live, even including the commandments or direction I receive from the Holy Spirit on a daily bases. Being a lawyer, I know you understand the law is important to understand the case it is being applied to and to determine guilt.
"And how do those of us who are not 'observing torah' come to "understand" it?"
Here is an example of how I see it. Many years ago the idea of tithe was brought up to me, I wrestled with it. Tried some times to honor it but always would fall back to taking care of myself when the bills needed to be paid I didn't have the faith. Overtime I learned to live with in the command to tithe. And from that I learned about blessings to come from faith in trusting God to provide. I don't tithe directly now, I understand the principle and no longer fear being without monetary resources, God has always, and always will provide for me. I don't live in fear in this regard, I learned the principle of tithing. I see a person in need, or a cause that needs met, I just give based on the direction I am told by the Holy Spirit until I don't sense the need to do it anymore. There is no legalistic requirement, its just flowing and I am at peace about it all.
Sabbath is another. I understand the Law of Sabbath for me. It is resting in the work of God, not my works. It is an object lesson. Same as tithe, can I stop working one day to see what God can do, do I have the faith. The seven year land sabbath would be an even higher lesson of faith if I had a farm, but it still has application to teach faith on other levels. I don't worry about whether I am suppose to light a match or build a fire on a particular day, I don't think that is what it is about. I think it is about trusting God will provide.
And it's clear in my mind that the reason we are to understand the Law is so that we can understand the Love that is being given to us in the salvation work of the Son of God. Resting in that work is the demonstration of our faith, and not the faith in our own works that only really shows we are trying to save ourselves.