Is it permissible for a woman to shake hands with her brother-in-law?
It is forbidden for the woman to shake hands with her brother-in-law because he isn`t a Mahram (unmarriageable) of hers.
When is Istikharah (guidance prayer) Du`a offered, before Tasleem (saying asalamu alikum warahmatu allah wa barakatuh to end the prayer), or after it?
It is offered after Tasleem.
Does touching women temporarily forbidden in marriage nullify ablution?
It is prohibited to touch, or to shake hands with such women as they are considered strangers, and doing so nullifies ablution.
What is the ruling on someone who fasts but does not pray?
A Muslim must be diligent in fulfilling all obligations, and after the Shahadah, prayer is the most important duty.
● If someone abandons prayer out of disregard, they are considered a disbeliever, and their fasting is not accepted.
● If they abandon prayer out of laziness, they are still a Muslim, and their fasting remains valid, but they have committed a grave sin by neglecting prayer.