Except for the Chasdic Jews and those outside of Modern Orthodoxy, Judaism generally accepts that the Exodus isn't history and that Moses was not a historical figure.
While I remember the days of watching so many proudly answering questions in the Kingdom Hall during the Watchtower Study (back in my day we still used the paper versions of magazines--I'm in my 50s, don't judge me), and I would watch parents offering their children that (awfully illustrated) Bible Stories book, teaching them how this was all true, true, true--myself being born Jewish and now a Reconstructionist I still see remnants of this even in what is supposed to be the more "enlightened" liberal Jewish movements.
And I'm not even mentioning what happens in Hillel for example when an Orthodox Yeshiva boy learns from a professor exactly what you are discussing (because professors in Orthodox seminaries do tell their students more or less what you are saying and, reportedly, students literally go crying to their rabbis that "this can't be true").
But often, I've noticed, since the Reform movement made a turn in 1999 to adopt Jewish cutoms as "a response to secularism" (whatever that is supposed to mean), I've heard some of their rabbis say odd things that make them suggest that one can now choose--at least in the Reform movement--to believe that the Exodus really did happen.
They never used to do that in their particular branch of Judaism. Like our own and the Conservative and even Modern Orthodox Judaism, the Exodus (as you have noted from reading even just a little of the footnotes from the NJPS Bible) is a redaction of mythology, legend, and folklore, all set in an order to teach the Torah. There is a reflection of something historical, but not a Jewish history--someone else's perhaps.
I am glad you touched on the Song of Miriam here. It is noted for being very ancient, the oldest litrugical song in Judaism (liturgical isn't the same as "historical"). But I was visiting a Reform synagogue the other day when it was being read, and the rabbi suggested we (the Jews) have been singing it since we (the Jews) crossed the Sea of Reeds.
I found that disturbing. I thought back to my days in the Kingdom Hall and crossed reference to my days in Hebrew School. We were taught critical scholarship in Hebrew school--that the Song is old, but because it is an old liturgical prayer, from maybe pre-Temple days, when there was just a shrine. But not that there was ever a sea-crossing event. It was designed to be sung to celebrate the Passover or maybe not even that, probably the Festival of Booths and that people had water to drink. It is the Song of Miriam, and Miriam is associated with wells of water that would be found in the desert, and the legends were as she was a prophet, she would lead the people to these oasis spots and the song would be sung in honor of that.
The legend from oasis spot crossings, from water spot to water spot, changed from crossing the Sea of Reeds, from Egypt to Sinai, from the female prophet Miriam being the leader to life to her brother Moses to freedom, all this as time went on. And that is what is believed happened and how we got her song placed after the crossing of the Sea of Reeds (and how we know it is not historical).
But I am not sure what to make of seeing hundreds upon hundreds of people just sitting there and listening to this rabbi and saying nothing in this Reform temple. This doesn't happen in the setting I am used to. People would have started chocking in their seats (not to mention tried to choke the rabbi afterwards) in a Reconstructionist setting. (I did not return, of course, even though the food was good. Jews love a good spread.)
I may have heard it wrong when he said what he said, but I don't think I did. I just kind of froze, and all I could think of was see a pair of JW children and that ugly Book Stories book with that yellow cover (and those flat, horribly drawn faces).
Please continue to post things like this. People need to know things these things. It's second nature to me, but for exJWs and many JWs who read this site who don't get exposed to the right materials, it's important eye-opening material. It's great that you are doing all this research.