Is Zakah (obligatory charity) due on leased property, and how is it calculated?
Zakah isn`t due on the leased property itself, but on the saved income from that property if it reached Nissab (minimum amount liable for Zakah), and a whole lunar year had lapsed over saving it.
My brother is settling a debt on my behalf and in return he takes 30% interest as an additional amount of the whole sum. Is this lawful or not?
This additional amount is considered prohibited interest (Riba) according to Islamic law, and it is not permissible to take it. And Allah Knows Best.
Is it permissible to pray with a heater (stove) in front of me?
There is no harm in praying with a heater in front of you, as long as you do not intend to venerate the fire or imitate those who worship it. And Allah Knows Best.
I suffer from excessive gas, especially when I pray, and I redo my ablution more than seven times. I have obsessive thoughts about this matter, even though I went to a doctor and was given medication that did not help. What should I do?
If the release of gas stops at certain times between prayers, you should wait for that time, perform ablution, and pray. However, if it is continuous, you should perform ablution after the prayer time begins and pray, and the release of gas during the prayer is excused. And Allah The Almighty Knows Best.