Sorry to say but don't rely on google timings. 
Malam Jabba road is in very bad condition 
. All the cars can go to Malam Jabba so a GLi can go as well.
Drive with patience or be prepared to have some permanent rattling sounds from different areas of the car specially doors.
Hotels: https://www.google.com/#safe=off&q=hotels+in+malam+jabba&hotel_dates=2017-05-30,2017-05-31&rflfq=1&rlha=1&rlla=0&rllag=34793806,72461661,10472&tbm=lcl&rldimm=1514712474538644174&tbs=lf_hd:-1,lrf:!3sEAE,lf:1,lf_ui:6
But there is nothing much to do in Malam Jabba during Summers, winters are fun there.
How you can go from Malam Jabba to Shangla Top 
, there is no such road which goes from Malam Jabba to Shangla Top. Please don't even think about it, it doesn't exist.
Security is not an issue 
.
Road to Malam Jabba is very bad 
, rest till Bahrain its in very good condition. You have to come back from Malam Jabba towards Fiza Ghat. You will two options the old road N95 and the new road on other side of the river which goes in front of the Saidu Sharif airport. The new road is in very good condition.
From Bahrain to Kalam, road doesn't exist. Better park your GLi at Bahrain and hire local fielder.
The road from Khawaza Khela to Balakot via Shangla Top is in good condition.
Balakot will be hot, better move up and stay in Naran or Shogran.
Your travel timings are absolutely not correct, I feel like crying 
considering you will have 4 children with you, planning to reach Lahore from Balakot in 6 hours and when you will be telling them, beta bas abhi Lahore pohanchne wale hain or Lahore nahin aana itne time me....
Same is the case from Kalam to Balakot in 6 hours, from where you got all these travel times???
