Very interesting. I see the story a bit differently than you because I see Israel as a means to the end of saving all men as opposed to Gentiles coincidentally being able to benefit from the salvation given to Israel. But, I still liked the article.
If you’d added a line about the first portion (and thus implicitly the second portion) of Romans 7 I think it would have fit your thesis tightly and would help people understand that tricky passage. I think some mention of the dynamic of Adam in Romans would be helpful.
I think you are starting to very powerfully get at the point of justification. Dikaiosune can mean either justification or righteousness depending on the translator’s whim throughout the NT and I think you’ve pointed out why it should probably be justification more often than we typically find.