I am looking at next years travel plans and have considered the HK and China flight pass. I have a few questions.

1. The AC site shows the pass as non upgradeable, will this change with the new Tango Plus pass eupgrade policies announced?
2. I am a soon to be SE, is there any or much chance of op ups on the pass.
3. How tight is flight availability on the pass, I had thought of getting one prior to an end of the month flight but there were no returns available at all.
4. If there is no availability in "G" class can you pay the difference to upgrade a class to get a seat.

It's a long flight from YYC to China with no chance of upgrade so I'm mulling this one over.

As an aside for those with HK knowledge, I am arriving Dec 30 about 10AM and leaving at 19:10 in the evening, we would love to go into the city for a few hours if there is time. Can I check in on arrival and does anyone have suggestions for a quick Hong Kong experience, getting into town and what to do?