Using someone's credit card and paying back with extra

Q: I live with my parents, and over the past few months, I've made some online purchases using my father's credit card (with his permission). Since there have been quite a few transactions, I’d like to repay him but it would take a bit of time to track every individual purchase. 

Is it permissible if I give my father an amount that is more than the total of my purchases, ensuring I cover the minimum amount I owe him? 

For example, if the purchases total $1000, I would return something like $1200 to cover any uncertainty.

Breaking up the journey when intending safr distance

Q: A person travels regularly between PMB and Durban. He has a daughter in Overport where he stays occasionally and he knows that till this point, he is not a musaafir. 

However, when he leaves PMB with the intention of visiting family in Isipingo (safr distance), but only after staying the night at Overport (meaning he will only go Isipingo the next day), will he be a musaafir from the time he leaves PMB? 

If, as above, he intends to visit Isipingo (the next day) and reaches Overport, but then changes his intention and decides not to go (as the family member is not there), will he be a musaafir? 

Similarly, if he leaves with no intention of visiting Isipingo, but only decides to visit Isipingo when he reaches Overport, will he be regarded as a musaafir (since the total distance with Isipingo will be more than safr distance)?

Husband being forced to sign a talaaq document

Q: My husband's parents forced him to sign a divorce paper. They prepared it by themselves and he doesn't know how many has been written. He didn't have any intention for this. Is it valid? 

They threatened him that his mother will kill herself while his wife put a pistol on her daughter. He did not know how many times divorce was written because he didn't prepare and read the papers, nor was he willing to sign.