What is the ruling on the yellow discharge that comes from a woman during pregnancy?
These discharges are not menstrual blood, but they are impure like urine and break the Wudu (ablution). If the discharge is frequent, its ruling is similar to that of urinary incontinence. The woman should perform wudu after the time of each prayer, pray the obligatory prayer, and any additional prayers she wishes, read the Quran, and take precautions against impurity to the best of her ability. Using a special pad can prevent the impurity from spreading. And Allah Knows Best.
Is it permissible for a woman to swear a false oath by the Holy Quran to please her distrustful husband?
It is forbidden for a person to do so since this is considered a false oath (Yamaan Ghamoos) which dips (Yaghmos) its taker in Hellfire if he/she doesn`t seek repentance, and he/she has to expiate for that oath. You should avoid any doubtful acts so that your husband`s chest remains clear from the evil suggestions of the devil.
What is the ruling on a man leading his sisters in obligatory prayer, or Taraweeh prayer (Night prayer in Ramadan)?
The prayer of the man who leads his wife, or sisters in prayer is valid, but it is more rewarding for him to offer obligatory prayer in the mosque. And Allah Knows Best.
Does the wife have the right to stop her husband from visiting some of his relatives because their meetings involve religious violations?
Couples should advise one another in kindness, and the wife can stop her husband from committing sin by resorting to a kind and tactful approach.