Can someone who begins a voluntary fast break it?
It is preferable for someone who begins an act of worship not to break it.
Allah the Exalted has said {what means}: "and let not your [good] deeds come to nought!" [Muhammad/33].
However, if a person starts a voluntary fast (nafl) and needs to break it, they are going against what is preferable, but there is no sin upon them.
If a father stops his daughter from getting married, is it permissible for her to conclude the marriage contract herself?
It is permissible for the father to stop his daughter from getting married if there was a lawful reason for that, and she isn`t allowed to conclude the marriage contract without her guardian. However, if her father denied her right in getting married for an unlawful reason, then she should go to court.
What is the ruling on delaying Zakat al-Fitr until after Eid day?
It is forbidden to delay Zakat al-Fitr beyond the sunset of Eid day. If someone delays it past Eid day without a valid excuse, they have committed a sin and must immediately make up for it because their obligation remains unfulfilled, and they must clear their responsibility.
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.