Bury them
No.
Some secular and Reform Jews think that cremation is acceptable.
No.
Yes, non-Orthodox Jews can become Orthodox by becoming more observant. Non-Jews can become Orthodox Jews through Orthodox conversion.
Orthodox Jews are strictly observant. Hassidic Jews are even more strict.
Orthodox and Ultra-Orthodox Jews are strict followers of Jewish law.
Unfortunately, in Israel, only Orthodox Jews get all the special privileges.
Haredi Jews are ultra orthodox Jews found around the world.
They are Jews who keep the Torah.
Orthodox Jews or Torah Jews.
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.
Reform Jews have only 1 seder instead of 2.