Hey there,
@240B! What you said struck me as funny, because I'm involved with part of the Jewish community in LA -- and my experience has been 100% the opposite ;). I think that's because there are so many Jews here, and many of them work together and with the larger community.
Some Orthodox Jews in the Pico/Robertson "hood" are very much separatist from other Jews as well as everyone else. They follow only one specific rabbi or rabbinic line; one group is Lubavitcher, for example.
In that same neighborhood are Conservative Jews who keep Kosher and the Shabbat laws but do not segregate themselves. There is another neighborhood in the San Fernando Valley that supports a smaller community of Orthodox and Conservative Jews with a variety of traditions.
Another example is the Israeli Jewish community at CalTech, which is extremely varied in terms of religious observance as well as anything else. Some of these families are involved in Chabad, some are atheists, etc. Most Jewish schools here are very welcoming to mixed families and even non-Jews affiliated with a synagogue. And there is one school in the area that was founded by Jewish scientists who valued the cultural traditions for their children but were not religious.
Re. conversion, I know Conservative synagogues that require ritual cleansing for new members and adopted children and ones that don't.
There is simply far too much diversity in the LA area for generalization, in my experience. But I'm really glad to say, that I haven't met anyone as prejudiced against non-Jews as you have.
