(1)The Christians certainly don't want a religion involving a special chosen race.
The word typically used in the bible translates as "tribe".
What christians want is all good and well, but god's chosen tribe is all over the bible. If you remember an OT story, chances is it's about the Israelites. Of course, apart from the big ten the OT is well-known to be nothing but filler to pass the time before god made himself Jesus. Certainly christians do not act as if it weren't.
But many christians do think they are special in some way (if not chosen). Personal relationships with omnipotent beings tend to fit that general bill ... The fact that judaism has found a way millenia ago to invite you to the tribe does not change that.
Also, the NT introduces the concept of heaven/hell, which is nothing
if not exclusionary.
(Also note that orthodox jews do in fact cling to a racial component.)
(2)If the Jews created the OT for that purpose, then why would they create laws protecting foreigners, allowing them to become a part of them if they so chose?
It's not about race, it's about tribe. Remember that "taking the enemy's women for their own" shtick. Remember all those rules dealing with the boring nitty-gritty of everyday life. It's about getting through the day, rules fit for a rather small group of people.
How long would such a group survive if it constantly went about abusing foreigners? What would be the benefit of turning away someone willing to join your way of life?
Note that whenever the bible comes to a point where the Israelites do have a sort of upper hand in any conflict, all that wimpy hippy crap about protecting foreigners goes right out the window. It does seem that there's precious little room in the bible between turning the other cheek and massacre.
(3) Why would they make up stories about how unfaithful they were?
While somewhat dull, this is a difficult question, rhetorically speaking. You have basically volunteered to speculate on the motivations of the original biblical authors, now there's no graceful way of excusing yourself from answering this one.
If you want to continue down that path, well ... cautionary tales? I hear they've been en vogue the last few millenia. Tales of suffering? Check. Redemption? Sex, violence, rule of law retribution, war? You can find counterparts of all of those in the literature of any period.
Plus, the bible wasn't written by one guy (although it's a nigh-certainty that women
had no part in this). It's not consistent. What one passage claims, another may ignore or deny.
(4) Why would they create stories about foreigners doing good deeds and being blessed by God?
Because it was that or remain an insignificant, much-loathed tribe in the podunk ass of nowhere?
Or, less facetiously, they still had to live in the real world. The Israelites would see that people of other religions weren't all vile and disgusting. People would still need to establish relationships (if only business relationships for the purpose of buying honey or selling goats or arranging marriages and what-have-you) with others who may or may not be sympathetic to the whole Yahweh thing. It's one thing to claim you have the truth, and another to alienate yourself entirely from everybody who disagrees.
Claiming to be in possesion of the perfect truth and yet being imperfect enough to not abide by it word for word is an ingenious feat of writing. It makes the Israelites' religion one of people trying to do their best, instead of one that's just better than everybody else.
The debate was going very well until he zeroed in on this even though it had little to do with the debate itself. Your thoughts on any or all of these 4 points?
Maybe he zeroed in on it at least in part because you have allowed yourself a somewhat speculative statement - and he's delighted that finally, even if it is in an area entirely irrelevant to the actual veracity of the christian myth complex, the burden of proof is on you. Let's face it, the motivation for coming up with a statement is formally unrelated to the merit of said statement.
There is little you can do besides reading the bible to argue your point. And yes, showing how the bible developed in a way indistinguishable from other religious texts is a good point when trying to show that the bible cannot be divinely inspired (or, at least, divinely correct). But on this specific point you are now arguing about historical truth where there is precious little data to go on.
Maybe it would be more productive in terms of the larger discussion to just cede the point and return to the discussion. Hopefully, he'd see just how small a victory that would be.