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.
Is it permissible to offer mandatory prayer while sitting?
All perfect praise be to Allah, The Lord of The Worlds, and may His Peace and Blessings be upon our Prophet Muhammad and upon all of his family and companions. Standing up is a pillar in the mandatory prayer and the prayer is not valid without it unless one cannot do it. As for Nafila (supererogatory prayer), one can perform it in the state of sitting even if he/she can stand, but his/her reward is half the reward of the person who prays while standing if he/sh has no legal excuse for such an act. And Allah Knows Best.
Who is required to give fidyah for fasting?
Fidyah—feeding one needy person for each missed fasting day—is required for:
1. Those who are permanently unable to fast, such as:
○ Elderly men and women who are too weak to fast.
○ People with chronic illnesses that have no hope of recovery.
2. Pregnant or breastfeeding women who break their fast out of fear for their child (fetus or infant).
3. A person who delays making up Ramadan fasts (qada) until the next Ramadan begins, without a valid excuse.
4. The estate of a deceased person who had missed obligatory fasts and had the ability to make them up but did not do so.
What is the ruling on the ablution of one from whom blood exits from his nose or a wound?
Blood flowing from a wound or a nosebleed does not invalidate ablution. However, performing ablution is recommended to avoid scholarly disagreement with those who make ablution obligatory after blood flows. And Allah the Almighty knows best.