Is Zakah due on the orphan`s money?
Yes, Zakah is due on the money of the orphan.
Is it permissible to pay the Zakah (obligatory charity) for settling the debt of a deceased relative?
It is impermissible to pay the Zakah for settling the debt of the deceased since Zakah is paid to eligible recipients who are alive. As for the debts of the deceased, they are to be settled from the estate before dividing it amongst the heirs, but if the deceased didn`t leave an estate, then it is desirable for his/her heirs to settle those debts if they can afford them. And Allah Knows Best.
Does passing wind, from the anus without a smell, invalidate prayer?
If a person is certain of having passed wind even if it was with no smell, then both his/her ablution and prayer are invalidated, thus he/she should remake ablution and re-perform prayer.
What is the ruling on a person who insists on praying in a specific spot and becomes angry if someone else prays there?
ruling on a person who persists in praying in a specific spot and becomes angry if someone else occupies it
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
Our Master the Prophet ﷺ forbade a man from habitually claiming a specific spot in the mosque as a camel claims its place (to sit); scholars consider this to be among the disliked matters (Makruhat). It is therefore obligatory to advise this individual that whoever arrives at a spot first has the most right to it. And Allah the Exalted knows best.