Also, the Ten Commandments are foundational to our legal structure, not the origin or destiny. You correctly point out that we have more laws than just these 10... see previous point.
"Your whole argument boils down to this one statement: ... in my opinion."
Opinions are all we have my friend.
And no, my whole argument boils down to official government approval of a single family of religious belief is wrong.
"Those who believe in the origins of the law don't rely on their own fallible opinion."
The "Infallible." source you refer to so often results in disagreements on the details of implementation as to have resulted in one major split, one major schism and hundreds of variations some of which have even added more books in the last 200 years.
So, even if you consider it infallible, people are not, and it is people that implement the law. Therefore for a government to sanction a law and suggest that it is from an infallible source which therefore precludes questioning it's validity and then to implement it with inevitable human failings is dangerous and more appropriate to dictatorial regimes than a democratic republic.
" Also, the Ten Commandments are foundational to our legal structure, not the origin or destiny"
One more thing...
I'm not sure what you are saying, could you please rephrase?