They did very well. After the movie was over, we sat silent for a moment.....then I turned to them and said "Well, what did you think?" The overall response was just....."wow". I have a book that specifically answers questions about the movie, so we went through it and had some great discussions about it.
Not everyone will agree with this (and I totally respect that), but....although you can not ignore the blood and violence in the film, it is truely a love story.
And the last 30 seconds of the movie leaves you with a great feeling!
It's hard to say how your ds would react to seeing it. I know he is "fragile" right now, and I also know he is very religious. So, maybe it could help, but maybe it would be too much, as you said. One thing to consider is that there is a "toned down" version of the movie that was released like a year after the original. I have not seen that one to compare, though.
I often think of you and your ds, and offer continued prayers.