Electricity is not of much issue, they use small turbines over flowing waters, voltage is low to charge the rechargeable things. Being short and to the point, you will not be sitting in darkness wherever you will be staying, they have arrangements.
As far as telecom services are concerned, in January 2015 during my last visit to Neelum valley scon was reached just to Kundal Shahi and Kutton. Don't not know recent situation. But there are so many landline PCOs in almost all the towns like Authmuqaam, Sharda, Kel etc so no problem in case of emergency calls.
Sir Neelum valley is heavenly beautiful specially from Sharda to Taobut. And those who have explored it fully like Jagran, Shountar, Taobut, Ratti Gali, Chitta Katha Arang Kel etc knows there is no second in Pakistan to the beauty of Neelum Valley. You will have to compromise on few small things like telecom signals, bad raod and lack of some facilities but its worth seeing although it will be just an introductory trip.