I think you have been well guided by the other senior members. I'm not sure whether you have revised your itinerary in the title post since you first posted it, but it looks fine to me. Whether it's six hours or eight hours, the bottom-line is that you can easily reach Naran in a day. You can also comfortably do the Naran-Rama leg in a day. You can do Rama-Hunza in half a day. I'm not sure about Hunza-Khunjerab and back in day (because I haven't been to Khunjerab). Two days stay in Hunza is good enough and the return itinerary is also fine. PTDC Rama room rate is Rs. 4,500 per night. You can get a good enough hotel in Hunza for the same amount of money. I don't know about room rates of Eagle's Nest (a good option), but it is expensive.
I have mentioned drive times in days rather than hours because drive times are very flexible in these areas depending on the number of stops you make along the way and their duration etc. You might also come across unforeseen circumstances. For instance, this year about a week after Eid, the KKH got completely blocked for traffic near Thatta Pani for a day or so and restless travelers like me had to take a narrow alternative road on the west bank of Indus.
I hope this adds to the knowledge already shared by other members and helps you plan better.