1.... a) May to October via KK highway
b)July to september via Naran, babusar pass
2.....a) (messy and lengthy) all good except between Dasu and Chilas
b) (cooler temperatures & shorter) all good except Naran entrance
3)....a) Lahore to Besham (Besham PTDC) , Besham to Chilas (Panorama & Shangrilla hotel) , Chilas to Hunza (cheap to expensive...many options availablle)
b) Lahore to Naran (cheap to expensive ...100s of options available) , Naran to Hunza via babusar pass
KINDLY REFER TO GOOGLE MAPS AS WELL FOR BETTER UNDERSTANDING OF ROUTES .. they may not be time accurate but you will be able to see the whole route!
4)Hunza valley: Eagles nest, altit baltit forts etc.... Attabad lake.... Khunjerab pass