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.
Is it permissible for a praying person to make supplication in each Sajdah (a prostration) of obligatory prayer?
It is permissible for a praying person, whether praying individually, or in congregation, to make supplication during Sujood (prostration) in obligatory, or voluntary prayers. However, it is disliked for the Imam to do so since he is required to spare the prayer performers any sort of hardship, unless he is leading a certain group who don`t mind him extending the prayer.
Is it permissible to combine and shorten prayers at home before traveling?
It is impermissible to combine and shorten prayers at home before traveling because a person is called a traveler once he/she departs the borders of his/her country, and offering prayer that way was originally intended to exempt a traveler. And Allah Knows Best.
My husband discloses all our marital disputes to his family. What is the ruling of Islamic Law on this?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is impermissible to divulge spousal secrets or expose one another's faults, whether during the subsistence of the marriage or after its dissolution. The foundational principle governing marital relations is that it is built upon confidentiality and mutual affection. Divulging marital secrets constitutes a breach of trust and a grave sin.
A husband ought not to resort to his family to complain about his wife over every dispute, nor is the reverse permissible for the wife, especially when such actions lead to stirring up malice and animosity between the spouses or between their respective families.
Islam has enjoined the preservation of secrets in general and commanded against revealing them; safeguarding the privacy of the home holds an even greater priority. And Allah Almighty knows best.