Interest money

Q: I want to apply to study in Canada and for this purpose I need a GIC certificate. A GIC is an account which I will open in a Canadian bank to show that I can bear their living expenses. When I go to Canada, they will refund me my funds within a given period of time along with interest. As a Muslim, interest is completely prohibited in Islam. What should I do?

Does a promise constitute an oath?

Q: If one makes a promise by accident or something they don't want to say comes out of their mouth as a promise to Allah, does the promise have any effect? If a married woman says Allah, I promise not to have sex with anyone and thinks she also included her husband in this, has she promised not to have sex with her husband and will she be sinful to have sex with her husband?

What if a woman explicitly promises not to have sex with her husband by mentioning her husband in the promise. Will she be not allowed to have sex with her husband and will she be sinful for having sex with her husband? 

Girl under 18 getting married

Q: I am 17 years old. My mother has passed away last year and I am living with my mamo and nano. I am totally burdened to them. My sister got married last year. They want me to also get married. I am biologically 19. My age was change in childhood. Can I get my nikaah since I've heard that girls under 18 cannot get married?