Q. Someone who is preparing himself to become a Ger and is already enrolled in a learning program, is in contact with the Beis Din and attends regularly a Shul, Can he be dance with the Torah on Simchas Torah or be given pesicha of the Aron Hakodesh or Gelilah?
If he owns a lulav and esrog can he do hakafos around the bima or the mitzvah of Hoshanos?

Can he be invited to say a dvar Torah on a kidush?
Thanks

A. There are certain mitzvos that a Gentile is not allowed to observe even when his intention is to become a ger, such as Shabbos. (Sanhedrin 58, Rambam – Melochim 10: 9, however, some Poskim permit after becoming circumcised). He is prohibited to learn Torah excepting the parts that are relevant to his observance of the seven mitzvos, the Tanach or written Torah (Meishiv Dovor 2: 77) and basic Halacha, if he is considering conversion (Mitzpeh Aryeh (2 Y.D. 8). He also should not don Tefilin since they have inherent kedusha and they require corporal cleanliness or hold a Sefer Torah or Mezuza (Ridbaz – H. Melochim 10: 10).

Following the above, Chashukei Chemed (Yuma 4a) rules that on the onset a prospective ger should also not be honored yet with pesicha (opening) of the Aron Hakodesh although the Rambam and others would permit. Besides the issue of Kovod or honor of the Sefer Torah involved there are other concerns such as Kovod Hatzibur and the fact that he may be equivocally accepted as Jewish even before he has fulfilled entirely his conversion (Aterez Paz O.H. 2)

Horav Shlomo Miller’s Shlit’a opinion is similar.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a