Interest Transactions

Q: Are any of the following Interest Transactions?

  1. If a person says "Buy this item for me when you go to the supermarket, it costs R40,but I will give you R50 tomorrow?
  2. Loan me R40, I will give you R50 tomorrow, the extra R10 is a gift?
  3. A person gives me R50 and says "Go buy this item for me, it costs R40 and you can keep the change?
  4. If the person insists on giving the extra amount even when I tell him that it is Interest, what should I do with that money?

Premarital affair

Q: I have been going out with a Muslim guy for a while. We shared a lot of things and I love him. I'm positive he loves me too. His parents say they heard some things about me and they won't say who told them but they don't want their son to be with me. In Islam what should have happene? I
mean he decided to make his parents happy and leave me after everything we've been through with each other. I need a point of view from someone who would know please advise.

Washing off urine

Q: Does getting urine on one's body require that person to perform ghusl? Because in old age sometimes one gets a few droplets of urine on oneself
without knowing, what should one do in that case?