If u read the laws at the back side of ur registration certificate. Its written that its liable for commercial purpose vehicle to keep the orignal registration certificate in the vehicle. For all other vehicles you have to produce it on demand within few days (I think 10days).
No attestaion in required. You must have a valid driving license and CNIC at least for challan purposes. Otherwise Officer can withheld ur vehicle.
As for ppl without licences, ill say its no bravery in showing irresponsibility. The problem starts if u hit any person or car... then the prosecution will be under heavy sections. even 302 sec for murder. if u kill any person.