Cathay Pacific Asia Miles - Long HKG Layover - Questions

I am getting the 3.05am flight from Shanghai to HKG and then departing 10 hours later to Vancouver.
I presume I can get my boarding pass in PVG and on arrival walk straight to immigration and out?
However is it possible to go to a lounge and drop off my laptop bag before going to Central?
I intend to do christmas shopping, can I check in another bag once getting to check-in again? I am flying biz class.

Thank you.

Yes.
Yes - you can go through the transit to the lounge when you arrive, explain the situation to the lounge attendants, and they will store your bag and give you a pass that will get you back to the arrivals level.
Yes - simply go to the check-in desk (you can use the F desk as BA Gold) when you return to the airport, or even at the Airport Express check-in.

in hkg only the f section of the lounge has "left luggage" but as a BA gold you will be in the F section anyways