A pious man proposed to me and my father was hesitant in this regard because he is black, am I sinful if I accepted his proposal?
If the suitor is pious, color isn`t a drawback. However, try talking to your father kindly, so that he approves of your marriage with contentment, and that is better for you.
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 a condition for I‘tikaf to be performed in the mosque?
Yes, for I‘tikaf to be valid, it must be performed in a mosque. I‘tikaf is not valid if performed at home or elsewhere.
If someone fasts on the White Days with the intention of making up for missed fasts (qada), will they receive the reward for both voluntary and obligatory fasting?
Making up missed obligatory fasts (qada) is mandatory, and the intention for qada must be specified.
If a person makes up their missed Ramadan fasts on the White Days, they must intend qada, but they may also intend to fast the White Days, and Allah willing, they will receive the reward for both.
This is similar to entering a mosque and praying an obligatory prayer, where the person also earns the reward of Tahiyyat al-Masjid (greeting the mosque) if they intend both.
● If the person missed their fasts due to a valid excuse, they may wait and fast on the White Days.
● However, if they missed the fasts without a valid excuse, they must make up the fasts immediately and should not delay them until the White Days.