I made a vow "If the Israeli troops retreated out of Gaza strip I will buy a cake from a certain bakery" and it happened. Am I obliged to buy from the same bakery?
You are obliged to buy from the same bakery. And Allah Knows Best.
Does a Quran broadcaster sin if he shift to another surah or chapter without informing the listener?
The Quran must be broadcast as it was recited by the reciter and in a manner that conveys respect and reverence. And Allah The Almighty Knows Best.
What is the ruling on making up for missed fasting after the second half of Sha`ban (the month before Ramadhaan)?
One is obliged to make up for missed fasting before the start of next Ramadhaan, and regardless of offering it during the first, or the second half of Shab`an. This is because the prohibition mentioned in the Hadith is for offering absolute voluntary fasting in the second half of Sha`ban. And Allah Knows Best.
Is it incumbent on a family to provide for its old handicapped son and take care of him?
The family and relatives - e.g. brothers - of such a person are obliged to spend on him and take care of him if he didn`t have money of his own.