Pakistani HongKong for Lighting exhibition in October

I am from Pakistan. Working in shenzhen. I need to go to HongKong for Lighting exhibition in October. I will get invitation letter from HKTDC (Exhibition organizers) for visa. What I want to know are:-
1:-How much is the fee for Business application?
2:-Should I pay extra fee of courier if I send my documents to HK Immigration in HongKong, So that they can send me the result(later to be pasted on my passport)?
3:-Which bank in shenzhen should I submit my fee in, the draft of which can be accepted by HK immigration?
4:-Should I plan and send my itinerary along with application? Cause I am in Shenzhen, Right next to HK, and I can take a metro,bus or even fairy to get there in Half hour. Will it be necessary to book hotel and travel tickets to show in my itinerary? My residence in HK will be arranged by my company later, just before the time of HK Autumn Lighting exhibition.