Chulent,
You take a very academic approach, which is what others accuse me of.
Jacob Katz wrote extensively on how living in a Christian world heavily influenced the psakim of Rashi, Rabbeinu Tam, Rema, and other Ashkenazi poskim on the status of Christianity.
Granted that we live in a Christian society, as well, perhaps we should consider these opinions so that we have good relations with our neighbors.