Thanks Ahsan for a detailed comment 
It is a practice in entire Sindh (the official spelling of Sind has been changed to Sindh in the 18th amendment to more properly reflect the sound) especially in the night that one or two policemen stand there and flash torches in cars. In day time they wave you over. Many people told me not to stop if the policemen don't have a patrol car. Even if they have a patrol car they won't chase if you don't stop because they're not there to stop outlaws. They're there to stop genuine tourists who pray for the honour of themselves and their women. This is the looters' strategy: finding an easy victim. People with families don't usually fight, they have too much at stake.
They will ask you questions like car reg book, third party insurance, authority letter, driving license (remember black policemen can't ask you for license, only traffic policemen can), highway permit (Don't know what the hell it is, but I mean), anything that you don't have just to extract money from you. If they don't find any problem with your documents etc. they'll just ask you like a beggar, '[I]bhai kharay hen tumharay dhoop men chai to pila do[/I]'. Looting a traveler is world's easiest crime, and they are there for this. In fact these remote check posts with no food/toilet/shelter are the most sought after because of these 'earning facilities'.
However it is not advisable to lose your temper. They will instantly produce a [I]charas ki purya[/I] from you and you'll land straight in lock-up, jeopardizing your trip and family (or otherwise rate will go up). Lots of transporters either give monthly or keep Rs. 20 notes handy. They merely slow down (this type of policemen usually stand on speed breakers or some pothole etc.) and press the note in policeman's hand.
And the policeman who told you that such policemen have been changed most probably is right now having a laugh. You can't change hundreds of people overnight. Plus who have been changed must have been embezzling with others' 'cut' and thus removed.
Everyone is aware of legal requirements and the fact that only traffic police can check driving licence and tax documents. ACLC letter is required only if the vehicle is being transported through truck. But as you have mentioned that we have to be very careful while having women and children with us. In the middle of highway these people do not accept any reference of their high-ups sitting in Karachi or Islamabad. Otherwise-- everyone can share some very 'good teaching experiences' with these culprits in the major cities.
However I will never advise to ignore a stop sign by a uniformed person. I always stop whenever I am asked to. I have taught my children to respect uniformed persons and say Assalam Alaikum Uncle to them. It is my part of the contribution to this society as I believe in 'be the culture you want to see'. These people are creating their desired environment for their children and I am trying on the culture I want to leave for my kids.
It is because of things like this that talented people who go from Pakistan to study/earn never want to come back.
This is another problem we are facing as a nation.
Looks like truck wanted to walk like humans/animals (one foot after the other) and ended up like this.

Showing the hind of a truck and praying 'meray saajan dua karna'? What sort of joke is this?
Chachu I am just reading what was written on the truck 
This is the bane of traveling with children. They need the loo so many times. This way no matter how many trucks you overtake, you have to put in the effort to pass them all again since you stopped and they didn't. Adult diapers[/URL] (& child diapers for children as well) could help minimize driving effort.
Well the stopovers at different places could be counted as fun as well.
Wrong! This road (13 km long) connects Super highway (1km from Northern bypass interchange and 1km from Toll Plaza on the other side) to Sharae-Faisal at Malir halt bus-stop while [I]passing in front of Malir cantonment[/I] gate no. 6. You don't have to enter Malir cantt and face all those security related, ummm - things. At gate no. 6 there is an intersection at which University road ends.
This is what I have mentioned in a simple and brief way -- without going into inches and millimeters of the road :)
Anyways nice trip. Now Mrs. RZ should get a good D-SLR and attend some photography classes.
Thanks for the appreciation brother.
Mrs. RZ photographed very well-- our objective achieved. I removed the digital camera to cut down on the number of gadgets in our luggage. However we will ensure improvement in our next course of action 