The value of Pak Rupee will be directly dependant on following things:
1. The amount of export we are able to do
2. The amount of remittances we get from abroad
3. The amount of principal repayment + interest on loans we have taken (including CPEC)
If imports continue to increase and exports do not grow faster than that, then value of Rupee will depreciate no matter who is in the govt.
If CPEC does not generate economic activity (say transit tax) in terms of dollars, it is going to hound us and cost us dearly when the original principal and interest are to be repaid. Remember, CPEC is no investment but a loan and its repayment starts from 2019.
The only way we fill the gap between out huge import bill and meagre exports is dollars earned be remittances. Otherwise, more loans will have to be taken unless our remittances increase dramatically (unlikely scenario).
So, Dar or Tareen or Shaukat Aziz or Asad Umar, economics 101 will determine value of rupee. You cannot continue to spend more than you can earn. Its only a matter of time your credit card will run out of limit and you'll have to pay back (with interest).
Dar did the credit card shopping while keeping dollar at 108. Now is the time where the limit has reached and credit card bill is arriving and that is why dollar is at 140. Bring back dar, he will get another credit card, take more loans to pay current ones and give you temporary relief. But know that when he leaves again, you will be left with bills from two credit cards and have double the trouble.
The only way forward is to bear the hardship and start living within your means.