Question
Can I take a tune of a Christian song and change the lyrics to make it Jewish? Is it permitted being that it is a mitzvah to turn a church into a synagogue?

Question
If one has to take a job that involves doing something that could lead to deaths (e.g. manufacturing bombs for a country not yet at war, but talking about it) in order to earn enough money to save your brother's life, is it ethically acceptable to take this work? (Situation in a novel I'm writing.)

Question
Hashkiveinu Prayer at Maariv ends differently on weekday night versus Friday night. Weekday Baruch ata Adonai Shomeir Amo Yisrael La-ad Baruch ata Adonai eternal guardian of Your people Israel. Friday night Ufros aleinu sukkat shelomecha Baruch ata Adonai ... v'al kol amo yisrael v'al yerushalayim May You spread over us your canopy of peace Baruch ata Adonai ... over all the people Israel, and over Jerusalem. Please explain the differences and the reason that the prayer is different.