What is the ruling on deliberately breaking the fast while being capable of fasting?
Whoever intentionally breaks their fast in Ramadan without a valid excuse has committed a major sin and bears great guilt. They must repent, seek forgiveness, refrain from eating and drinking for the rest of the day, and make up for that day after Ramadan.
They have lost an immense reward, which cannot be compensated even by fasting an entire lifetime as a voluntary act, because an obligatory fast cannot be equaled by voluntary fasting.
If the fast was broken through sexual intercourse, the person must:
● Make up for the missed fast (qada), and
● Perform kaffarah by fasting two consecutive months.
● If they are unable to do so, they must feed sixty needy people.
Is Zakah (obligatory charity) due on the Zakah money received by a poor person, and reached a Nissab (minimum amount liable for Zakah), and a whole lunar year had lapsed over having it in his possession?
Yes, the poor who possessed a Nissab for a whole lunar year is obliged to pay the Zakah due on that money even if it was given to him as a Zakah money in the first place. And Allah Knows Best.
Is the son of the sister by breastfeeding considered a mahram in Islam, and is it permissible for a woman to go for Hajj with him?
Everything that is prohibited by lineage is also prohibited by breastfeeding. The son of the sister by breastfeeding is considered a mahram, just like the son of the sister by blood, and it is permissible for him to be her mahram for Hajj and Umrah. 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].