a) Capt/FO/Sec Off never get upgraded to First of Business?
Cathay does not have an upgrade on space available policy, or anything similar for ID travel
b) if no Econ Seats are avail but First and Business are- you won't be accepted on the flight?
If you list, and standby for econ. and there are no seats available, you will not get on UNLESS the ground staff upgrade a fare paying pax to make space for you.