Holding the Qur'an and taking a false oath

Q: 

  1. A person who has two wife's and at present is living with the fist wife, the second wife made the husband touch the Qur'an and made him say I am your only wife and the first wife isn't my wife she (fist wife) is my sister. The husband said this to make her (second wife) happy and when saying this he had the intention that the first wife is also his wife, what is the Shariah ruling for all this?
  2. Will the second wife  be sinful for making the husband say the above touching the Qur'an?
  3. Will the husband be sinful for touching the Qur'an and saying the above?
  4. By doing the above does it effect the Nikaah in any way?

Doubting if one has settled his accounts during his student days

Q: A person has been attending a madressa. At the madressa there is a tuck shop which allows the students to take things on credit. As a student many things were bought on credit and paid later. A few years later the student has doubts in their mind as to whether they have paid their accounts accordingly. What can the person do besides asking Allah for forgiveness?

Working as a teller in the bank

Q: I have a job interview working for a bank in the USA. I was told that it is haraam to work for an American or foreign bank because they deal with interest rates (RIBA). However when I work there I will be at the cashier, depositing the clients money in their account, not directly with riba. Please advice if this is haraam or halaal?

Khilaal of the toes

Q: Regarding khilaal of the toes, should one make khilaal of the toes of both feet together after washing both the feet or should one make khilal of the toes of the right foot after washing the right foot and of the left foot after washing the left foot? What is the sunnah method?