Is it permissible for a woman to uncover her face while performing Umrah (minor Hajj)?
The woman while in a state of Ihram (ritual consecration) is obligated to uncover her face and hands, but at the same time permitted to let her head-covering garment drape from her head down over her face when non-Mahram (i.e., marriageable) men pass by her. And Allah Knows Best.
What is the ruling on using a patch to suppress hunger or a nicotine patch while fasting?
Fasting is a great act of worship and one of the pillars of Islam. If people knew the immense reward of Ramadan, they would wish for the whole year to be Ramadan.
Whoever eats Suhoor and breaks their fast according to the Sunnah will not experience extreme hardship, making such patches unnecessary.
However, using these patches does not break the fast because they are not a source of nourishment and do not enter the body cavity (jauf) through an open passage.
Can I start fasting based on the moon sighting of another country?
You must follow the moon sighting of the country you are in.
Is it a condition for the mosque where I‘tikaf is performed to hold Jumu‘ah prayers?
No, it is not a condition for the mosque where I‘tikaf is performed to have Jumu‘ah prayers. However, if a person vows to perform continuous I‘tikaf, and Jumu‘ah occurs within that period, then they must observe I‘tikaf in a mosque where Jumu‘ah is held so that they do not break their continuity by leaving for Friday prayer.