Should missed Sunnah prayer be made up?
Making up missed voluntary acts of worship is from Sunnah.
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 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 should a person, who doubts the validity of his Wudu, or over performs it, do?
One who doubts the validity of his/her Wudu while performing it should redo it until he/she is certain of having attained purity. But, if doubt was after having performed Wudu, then he/she should not pay attention to that as doubt after the end of an act of worship does not count. This is of course in case doubt was within the reasonable limits since once it goes beyond that, it becomes a whispering of the Shaytaan (devil) which he/she should ignore as the Wudu is valid.