1- Is it the right time to visit there & what would be weather like?
Yes right time, weather pleasant to cold.
2- Any trustworthy tourist guide contacts who can accompany with family members?
You dont need any guide there.
3- Reasonable priced hotel detail for each locality?
September it will be almost empty, you can get a hotel of your choice and at your rates. .. around 1500 to 3500.
4- What should be Itinerary from Islamabad?
You said 10 days, thats too much for Naran.
Day -1 Leave ISB 9am, have lunch in Balakot, after lunch go to Shogran, stay a night up there, will be very cold.. Shogran is about 250km from ISB.
Day -2 leave Shogran for Naran, on the way there are many places you can stop and take pictures. Stay a night in Naran, its about 70kms from Shogran.
Day - 3 Go to Lake Saif ul Muluk, stay few hours up there, come back to Naran for lunch, after Lunch see Naran city.
Day - 4 Leave Naran and go to Babusir top, it will be shriving cold up there, do check with locals if its open. Stay an hour up there and on the way back stop at Lulusir lake... back to Naran
Day - 5 Leave Naran go to Lalazar, back to Naran
Day - 6 Come back to ISB or stay there and enjoy the weather for few days.
5- How to avoid scams & getting ripped off by overcharging?
It will be off season, want be many rippers there. 
I hope you are not going on Eid holidays, if yes dont go, you wont find a single room to stay in.
