Is it permissible for a wife to refuse to go to bed with her husband (for sexual intercourse)?
It isn`t permissible for her to do so unless for a sound reason.
What type of illness that permits breaking the fast in Ramadan?
It is an illness that, if one fasts, there is a fear it may lead to their death or cause unbearable hardship.
Do pregnant and breastfeeding women have to fast?
Pregnant and breastfeeding women are required to fast. However, if fasting causes them harm or unusual hardship, they may break their fast but must make up for the missed days later.
If they break their fast solely out of fear for the fetus or the child, then they must both make up the fast and give fidyah (feeding a needy person for each missed day), as the benefit of breaking the fast was only for the child.
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.