In interior Sindh you should exercise caution because of robberies etc. Just don't stop your car for anyone. Punjab onwards, it is safe.
You can stop at Sukkhur but must stop at Rahim Yar Khan (which is halfway, around 650km) for rest and food etc. Going forward, you can stop at Multan (300km from RYK) and then Lahore. Lahore onwards you will be travelling on motorway so it will be a breeze. 95%+ of the road is in excellent condition and there are plenty of restaurants, petrol pumps along the way. Just make sure you have on extra driver and that everything is in order e.g. tire pressure, battery, other electronics etc. Also getting tire pressure checked at regular intervals during the journey would be a good idea.
Do take jumper cables and towing rope just in case