Regarding your latter point:
“But I do not think that there is any point in going on the offensive and trying to “refute” their religion. And, as an aside, I do not think historically we ever have done so. “
I agree, to a point, though I believe this is also an important point to discuss with one’s LOR.
Personally, I believe that every Jew should be quite clear that our faith is very obviously the one and only Das Emes, and that no others can, neither objectively nor even subjectively, derive support from our holy Torah.
I’m not 100% comfortable with your use of “defensively”, as it implies that there is what to defend when there really is nothing to defend since their “arguments” are based on mistakes and/or worse.
Again, dealing with these matters is a sewer; ask an LOR what, if anything, to do.
On a related note, Hashem obviously placed these other faiths in the world for a reason. So, for example, if non-Jews live more moral lives as a result of their faith, then that’s great for everyone. We do not look to proselytize. In fact, we seek to NOT proselytize.
But, lihavdil, we have the forever-enduring and absolutely permanent das emes, and we should be crystal-clear that this is the case.