Is it permissible for household members to pool money for the Udhiyah and gift it to one of them?
Praise be to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is permissible for members of a household to pool their money together and gift the total amount to one individual among them so that he may offer the sacrifice (Udhiyah). In this case, the family members receive the reward for giving charity (Sadaqah), and the one performing the sacrifice includes them in the spiritual reward (Thawab).
Furthermore, slaughtering a single sheep (on one's own) is considered religously better than participating as one of seven people in the sacrifice of a cow or a camel. And Allah the Almighty knows best.
How many Rak`ahs (unit of prayer) are offered in Witr prayer?
All perfect praise be to Allah, The Lord of The Worlds Witr (an odd number prayer performed between Isha`a and Fajr) is offered with a minimum of one Rak`ah, and a maximum of eleven, but offering three Rak`ahs is the minimum of its complete form. And Allah Knows Best.
What is the ruling on performing Tarawih in sets of four rak‘ahs with only one Tasleem?
It is not permissible to combine more than two rak‘ahs with a single Tasleem in Tarawih prayer. Whoever does so, their prayer is invalid. Shaykh al-Islam Imam Muhammad al-Ramli (may Allah have mercy on him) stated: "If a person prays four rak‘ahs of the Tarawih prayer with a single Tasleem, it is not valid if they did so intentionally and with knowledge [of the prohibition]. Otherwise, it becomes an 'absolute voluntary prayer' (nafl mutlaq); because it is contrary to what has been prescribed." [Nihayat al-Muhtaj, Vol.2/P.127].
How is the beginning of Ramadan determined?
1. Completing 30 days of Sha‘ban, or
2. Sighting the crescent moon after sunset on the 29th day of Sha‘ban.
It is Sunnah to search for the moon, and it is obligatory to follow the official authorities responsible for announcing it.