The "eye for an eye" makes some sense in your description, as it seems to be against other biblical directives.

Where can I look into your statement "It is considered heresy to view the Bible/Tanakh as the last word on a law."?

This is is a new idea that I had not heard before, and it would explain a lot of discussions I have had over the years if I understood it's source. (I keep the sabbath, annual holy days, but not the Jewish laws, so I have had some interesting discussions over the years)

Orthodox (and broadly, "Rabbinic") Judaism place equal weight on the "Oral Torah" – a set of evolving traditions and insights which orbit the written books in vast and intricate constellations. To deny the validity of the Oral Torah is considered heretical. If you were to just follow the 5 books, and nothing else, most modern (Orthodox) Jews would say "that's not Judaism [as we understand/perceive it]".

For a bit more info I found this Quora question, which has some good answers: https://www.quora.com/Do-people-of-the-Jewish-faith-interpre... (Only the first 3-4 answers, after which the answers divert into jokes, and a very odd fire 'n brimstone answer.)

Thanks for the Quora link, there is some very interesting comments there.