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 a wife to leave her house without asking her husband?
It is impermissible for the wife to leave her house without asking her husband except for a sound reason.
Is the one offering the sacrifice liable if its meat spoils?
Praise be to Allah, and prayers and peace be upon our Master the Messenger of Allah.
If the meat (of the sacrifice) spoils due to the negligence of the one offering the sacrifice in preserving it, or due to improper storage, then he is liable to compensate for the portion due to the poor (which is estimated as half a kilogram of meat). If the sacrifice was a vowed (mandatory) one, then he is liable for all of it.
However, if he was not negligent, then there is no liability upon him, because its ruling is the ruling of a trust (like an item left in someone's care). And Allah Almighty knows best.
What is the ruling on Zakat al-Fitr?
Zakat al-Fitr is obligatory upon every Muslim for themselves and for those they are financially responsible for, provided they possess wealth that is surplus to their and their family's needs on the night and day of Eid.
Ibn Umar reported: "The Messenger of Allah ﷺ made Zakat al-Fitr obligatory—one sa‘ (measure) of dates or one sa‘ of barley—upon every Muslim, whether slave or free, male or female, young or old." [Narrated by Al-Bukhari]
Its estimated amount is approximately 2,500 grams of wheat or rice, and the General Iftaa` Department issues an annual ruling specifying its monetary value.