Walking under a Ladder
Q: Is it forbidden to walk under a ladder which is leaning against the wall?
A: Not walking under a ladder is a Christian superstition. The leaning-ladder makes a triangular shape that recalls the Trinity, and walking under it is considered a desecration of their faith. One should, however, be careful when walking under a ladder that no object falls on him, and all-the-more-so that the ladder itself doesn't fall on him or anyone else (Ner Be-Ishon Laila p. 234).
Addition in Musaf of Rosh Chodesh
Q: During a leap-year, we add "U-le-Chaparat Pasha" into the Shemoneh Esrei of Musaf. When do we stop saying it?
A: There are three opinions. Mishnah Berurah (423:6). The custom is to cease at the end of Adar Bet (This is also the custom mentioned in Luach Eretz Yisrael).
Father and Son - Yaakov and Yisrael
Q: For Ashkenazim, who are particular not to name a son after a living father, is it permissible for a father with the name Yaakov to name his son Yisrael, or visa-versa?
A: It is permissible. It is not the same name.
Street Named after a Rabbi
Q: When a street is called after a Rabbi, does one have to call the street Rabbi X or Y, or is it permissible to just say the last name?
A: Rabbi (see Tuvcha Yabi'u Vol. 2, pp. 17-19).
Earth as the Center of the Solar System
Q: Rabbi Nachman of Breslov held firmly that the sun revolves around the earth. How can we understand this?
A: It is indeed difficult to understand.
Informing a Family about the Death of a Tzahal Soldier on Shabbat
Q: Is it permissible to drive on Shabbat in order to inform a family of the death of a soldier in Tzahal?
A: Yes, out of a fear that the family will find out on their own, and this could be life-threathening to an elderly or ill person. It is obviously preferable that the driver be a non-Jew.
Smoking on Yom Tov
Q: Is it permissible to smoke on Yom Tov?
A: It is forbidden to smoke even on a weekday (Shut Tzitz Eliezer 17:21. Ha-Rav Chaim Kanievsky in She'eilat Rav 1:52. Shut Teshuvot Ve-Hanhagot 4:115. Ha-Rav Nisim Karelitz in a letter at the beginning of the book "Chaim Le-lo Ishun". Ha-Rav Ovadiah Yosef in Maran Pe'er Ha-Dor p. 31).
Wrapping Tefillin Straps around One's Fingers
Q: Sefardim put on the hand Tefillin while seated. Does the same apply for wrapping the straps around one's finger?
A: This is done standing. The same is true for removing them (Mishnah Berurah 27:8. Kaf Ha-Chaim 28:6).
Teachings of Rabbenu Ha-Rav Tzvi Yehudah
Q: What are the central tenets of the teachings of Ha-Rav Tzvi Yehudah?
A: Love and faith. Love of Hashem and Israel and faith in Hashem. Orot p. 69.