Question: May a shaliach eat before doing b’dikas chametz in his friend’s house?

Short Answer: There is a dispute whether a shaliach may eat before performing someone else’s mitzvah for him. Practically, it is probably better for the shaliach to refrain from eating beforehand unless he must.

Question: May a person under the age of 40 publish a sefer on halachah?

Short Answer: While there was a takanah in Prague a few hundred years ago not to publish, there are many leniencies to allow a talmid chacham to publish a sefer halachah nowadays.

Question: What should a shul do if it forgets to lein one of the four parshiyos (Sh’kalim, Zachor, etc.) on Shabbos?

Short Answer: There is a machlokes whether it may be read the following week. The Mishnah B’rurah rules that it may not be read the following week.

Question: Should a person residing in Yerushalayim go to Tel Aviv (or the like) to hear Megillah a day early, on the 14th of Adar?

Short Answer: Rav Yosef Dov Soloveitchik zt”l cites a machlokes Rambam and Ramban whether the 14th or 15th day of Adar is the main day of Purim. This author suggests that if the 14th day is the main day, perhaps it is preferable for someone in Yerushalayim to hear the Megillah on 14 Adar.