I think you are way-off when you say that Jews like to deal in their own community MORE than other people. I think most minorities deal within their own community. I will go further and say that the "like" comes from the fact that familiarity breeds familiarity - period. I do not go out searching for Jewish clients or Jewish contacts. I can say that earlier on I used to, and I used to feel more comfortable dealing within "The Tribe", but that's radically changed. In fact, some of the worst experiences I have had in business are when I've dealt with someone recommended through the community to me. They expect the relationship to be more personal than it is business, and that's not the way things work. Again, I suspect you would find this in any community though.
As for some Jews not agreeing with the existence of Israel, I suspect those would be few and far between, if at all. I strongly agree with the concept of a Jewish state. You have to realize that we are still in the shadow of the Holocaust, and the safety of having a place that we can both call our own, and a place that can stick-up for Jews is quite important.
Can Israel survive on its own in the Middle East - I suspect not. Imagine being surrounded ON ALL SIDES by countries that are larger than you and want to "drive you into the sea".