They were immigrants like everyone else.
Yes, non-Orthodox Jews can become Orthodox by becoming more observant. Non-Jews can become Orthodox Jews through Orthodox conversion.
Orthodox Jews are the people that want to keep tradition. Reform want 2 change things. I think that Orthodox Jews chose to break away from orthodox tradition and become reform Jews because they didn't like the whole tradition of orthodox Jews and all the rules they had to stick to such as observe all 613 laws as strictly as possible. So I think they changed so that they could have a bit more freedom from all these rules although there were still rules being reform Jews but at least if they change to reform Jews it changes (reform means change things).
No.
Orthodox Jews are strictly observant. Hassidic Jews are even more strict.
Orthodox and Ultra-Orthodox Jews are strict followers of Jewish law.
The Mosaic Laws are the laws that God gave to Moses. Jews are supposed to follow these laws to the best of their ability as a guide to being a good person and a good example to the people of the world. Jews who strictly follow the rules are simply religious Jews.
Unfortunately, in Israel, only Orthodox Jews get all the special privileges.
They are Jews who keep the Torah.
Haredi Jews are ultra orthodox Jews found around the world.
Orthodox Jews or Torah Jews.
Of course, Hassidic Jews emphasize the fact that they raise their children as Hassidic Jews, but in reality, there is significant intergenerational flow, with some children of Hassidic Jews departing for other streams of Judaism, and with some children of Liberal Jews joining more Orthodox streams. This seems typically human. There is a similar intergenerational flow between Christian denominations.
Symbols do not destinguish Orthodox Jews from other kinds of Jews. Orthodox Jews are distinctive in that they adhere to the idea of the of the binding nature of Jewish law.