Performing qasar salaah when studying safar distance from home

Q: I take Pietermaritzburg as my home (Wathne Asli), however due to me studying and being married, I live in Isipingo Beach and take Isipingo as my Wathne Iqaamat. If I stay in Isipingo for less than 15 days will I be a musaafir in Isipingo? Doesَ my wife have to follow my intention as taking Pietermaritzburg as my Wathne Asli and Isipingo as my Wathne Iqaamat, or can she take Isipingo as her Wathne Asli?

Breaking an oath

Q: One of my friends was a chain smoker until recently. Even after many attempts he was unable to give up smoking. Finally one day he took an oath by holding Quran paak in his hand that he would never smoke again. But after few days he started smoking again. So what is the kaffara of the oath which he took on Quran. 

Islamic banks

Q: Is it permissible to saver money in a savings account in an Islamic bank? We are only using the actual money which we have saved. Whatever savings profit we receive from the bank, e.g. 2% etc. will be given to the poor

Marital problems

Q: I am 27 years old. We are married nearly 2 and half years now. I am struggling to conceive due to imbalance of hormones and irregular periods. My husband has higher desire of sex compare to myself. I am trying my level best to meet up to his requirements but he is not happy and believing that I disobey him. I know and accept in Islam that a wife must show up when her husband calls her to bed otherwise she is sinful. He gets angry and frustrated with me and tells me that I should change my religion because I refuse him in bed. It is really quite worrying my life, I see no fault of myself if naturally I have less desire compared to him. But I am being scolded most of the time. My question is that what should I do in this case? Am I still sinful? How should we behave in this aspect? How should my husband treat me as I am naturally less desiring and most of the time I am meeting his requirement. I can say 90% of the time I do meet his desires. 

The acceptance of duas

Q:

1. What is the reason why wazifas don't work for some people and what are the conditions needed to make sure it works?

2. If you don't pray salah, will Wazifa never work or will it just work very slowly? What if you pray but not punctual?