Are minors obliged to fast?
A male under the age of puberty isn`t required to fast, but his guardian should order him to fast if he was able to endure the hardship until being used for fasting in general. And Allah Knows Best.
Is Iddah (waiting period) incumbent on an old woman whose husband had died?
Upon the death of the husband, Iddah is incumbent on the wife regardless of their age. And Allah Knows Best.
Is it permissible for a woman who broke fasting due to a delivery to pay a ransom?
She should make up for the missed fasting days once she becomes ritually pure, but it is impermissible for her to pay a ransom while being able to fast.
What is the ruling on having a second congregational prayer in the mosque?
All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions It is disliked to have a second congregational prayer in the mosque which isn`t visited by travelers like the neighborhood`s mosque, and which has an appointed Imam, save with the latter`s permission. Nevertheless, if the mosque is visited by travelers, it is permissible to have a second and a third congregational prayer, whether it has an appointed Imam or not, or whether he permits that or not. And Allah Knows Best.