If you are starting from Islamabad, its better to stay in Shogran instead of Mansehra,, there is no such views in Mansehra, but yes you can take a break and enjoy the views while crossing Mansehra,
To reach Shogran you have to take right side road just after Kiwai stop. Shorgan road is not very good and also not very bad, book the hotel in advance for Shorgan as there are very less options.
Shogran to Siri Paye, you have to hire Jeep,
Naran is over crowded, If you want to go to Lake Saif Ul malook, you have to stay in Naran or surrounding area, I would prefer to look for hotel at Naran Bypass road instead of Naran Main Road, but staying in Batakundi (few kms more from Naran) will be better if you are planning to go further.
In Naran area, have to hire a Jeep for Lake Saif ul malook, it take approx 1 hour from Naran to Lake.
Lulusar lake is on the way to Babu Sar after Crossing Naran.
You can cross Babusar Top on Mehran easily, there are few steep curves, you have to be careful, rest is ok.
At Babusar Top you may face cold weather, be prepare for that.
While descending from Babusar Top to Chilass, road is very steep with sharp turns, you have to keep the car under control. low gear and avoid excessive braking. you can descend in 1st gear easily.
Once you reach Chilass, there is nothing to see in Chilass
temperate in Chilass will be hell hot. The only good hotel in Chilass in Shangrila Hote.
From Chilass you can continue to Hunza on KKH road, Chilass to Rai Kot bridge road is not good, its approx. 65 kms and may take 2 to 3 hours.
After Rai Kot bride road is very good and you can continue your journey toward Hunza, Hunza is good place, you can stay there for 2 days while enjoying the visit to Altit Fort, Baltit Fort, Eagle Nest View Point, all these are accessible on car.
In Hunza there are multiple private guest houses which reasonable price and facilitates.
If time permits you can go to Khujarab Pass (China Border) from Hunza, it take approx 3 hours for once side. so If you start in morning you can easily come back to Hunza from Khunjarab before Maghrib prayer.
PS: From Naran to Babusar Top to Chilass, you have to travel in day time, you cannot travel after Asar Prayer.