It is likely that he converted to Reform Judaism because that conversion is much easier and Natalie Portman is not terribly religious (dogmatic) herself.
Orthodox Jews rarely accept converts, but if they do, they require several years of intense study.
Yes.If the person did an Orthodox conversion, they can be buried in any Jewish cemetery.If the conversion was non-Orthodox, they can only be buried in a non-Orthodox cemetery or section, such as Reform, Conservative, and Reconstructionist conversions.
Orthodox Jews believe their way is the only "proper" way to practice Judaism. In most cases, it's considered brainwashing.
No Jews, regardless of level of observation, seek converts. However, if people wish to convert, Orthodox Rabbis will assist them after being convinced that the potential converts are sincere in their actions. That being said, most Orthodox groups, especially Chassidim, try to get non-observant Jews more involved in Judaism.
Yes. Consult your local Orthodox rabbi. That rabbi will point you to an Orthodox rabbi who works with a beth din (Jewish court, consisting of 3 judges) that will supervise the conversion. Note that Orthodox conversion (like all conversions to Judaism under any branch of Judaism) is not simple. It requires on the order of a year of serious study, plus regular participation in Jewish services and, as you learn what you are getting into, increasing adherence to Jewish law and tradition. Furthermore, Jewish tradition requires that the potential convert be discouraged from conversion because it exposes you to the wrath of antisemites and because you don't need to be Jewish to be seen as righteous.
Vladimir I ordered his subjects to convert to Orthodox Christianity.
According to Jewish law, a Kohen can't marry a convert to Judaism.
Did Benjamin Disraeli convert from Judaism before becoming UK Prime Minister and was it then, and now constitutional requirement before, holding office
No. You would be Greek Orthodox then.
Yes. In Judaism, there is no distinction between a "Jew by birth" and a "Jew by conversion"; they are both inheritors of the Tradition and have equal religious rights, permissions, and responsibilities. However, the validity of the conversion might be called into question if the conversion did not follow Torah law. This is primarily a concern for those who convert to Judaism with a Reform Jewish Rabbi. Often, for example, such a convert, if male, will not undergo circumcision (or the drawing of a drop of blood if already circumcised), which renders the conversion incomplete and ineffective from an Orthodox perspective.
Yes, but Orthodox Rabbis try to dissuade them 3 times, so that they know if it is a sincere conversion. The potential convert has to learn relevant Torah-laws, such as Sabbath-observance, etc. Non-Orthodox Rabbis will interview the person and assess their motivations. They may require several meetings.
Yes. To do this, you will need to speak to a Greek Orthodox priest who will advise you of the process, which is usually fairly easy.