Is Zakah due on the orphan`s money?
Yes, Zakah is due on the money of the orphan.
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.
Is it permissible for the children of a deceased father to settle his debt from the Zakah (obligatory charity) money due on them?
It is impermissible to use the Zakah of one`s money for settling the debts of the deceased. However, children should settle the debts of their deceased parents out of filial piety. And Allah Knows Best.
What is the ruling on bypassing a nearby mosque for a distant one?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
If a distant mosque has a larger congregation (Jama‘ah) while the congregation in the nearby mosque is smaller, and the congregation in the nearby mosque is not adversely affected by the worshiper's absence, then it is better for him to pray in the distant mosque with the larger congregation. However, if the congregation in the nearby mosque would be affected by his absence—such as if he is its Imam, or if his presence encourages others to attend—then praying in the nearby mosque is better. This ensures that the congregation is established in two different locations within the community. This is based on the saying of the Prophet ﷺ: 'A man's prayer offered with another man is purer than his prayer which he offers alone, and his prayer with two men is purer than his prayer with one and if they are more (in number), it is more beloved to Allah, the Mighty the Majestic' (Narrated by Ahmad, Abu Dawood, and An-Nasa'i). And Allah the Exalted knows best.