Part 1
Despite local Ashkenazi custom, the Gra rules to say boreh nephashoth with the name of Hashem, following the Jerusalem Talmud and not the Bavli.
Part 2
The father makes a bracha when his son reaches bar misswah. He also makes a bracha in the repetition of the Amidah for Modim.
Part 3
Do you make a bracha for reading the meghilla? The Rama says no, but the Gra rules yes - deciding that the halacha here overrides minhag. He also rules according to the Yerushalmi regarding a baal keri.
Part 4
What's the deadline for saying the morning shema? Halacha after halacha, the Gra rules according to the Yerushalmi. Why?
Plus: The Bavli critiques itself as a book filled with doubts about the truth.