What is the ruling of Islamic Law on saying the basmalah at the beginning of wudu`?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
Saying the basmalah (Bismillāh) at the beginning of wuḍūʾ is a sunnah. It is stated in al-Minhāj al-Qawīm Sharḥ al-Muqaddimah al-Ḥaḍramiyyah (p. 27): “Its sunnahs include the siwāk, then the tasmiyah (saying Bismillāh), joined with the intention (niyyah), at the start of washing the hands.” And Allah Almighty knows best.
What is the ruling on ablution without istinja' after sleep?
The sleep of one whose buttocks are not firmly seated on the ground invalidates ablution. Whoever wakes up and wants to pray must perform ablution only. Istinja' is not a condition for the validity of ablution, because it is for removing impurity from the private part. If there is no impurity on the private part, then istinja' is neither obligatory nor recommended. And Allah the Almighty knows best.
Is it permissible for a woman to offer the obligatory prayer after Adhaan (call for prayer), and before Iqamah (The announcement that the prayer is about to begin) in the mosque?
Yes, it is permissible for a woman to offer the obligatory prayer immediately after the Adhan and before the Iqamah in the mosque. And Allah Knows Best.
When is a child instructed to fast?
A child is instructed to fast at the age of seven if they are capable of fasting and have reached the age of discernment, by analogy to prayer. They should be encouraged but not forced, so they can become accustomed to it. It is obligatory for their guardian, whether a father or another, to instruct them.