I'll be flying to HKIA and then continue with China Airlines from Shenzhen airport (SZX-TSN).

1. Could I check in (including printing of the flight ticket) in HKG airport for this flight (and go by ferry from HKG airport to SZX airport directly?)
2. Is it possible to buy the ferry tickets upfront? (or at least reserve them?)
3. At what time I should be going from HKG airport when I'll be flying from SZX at 7:20 pm ?

Thank you!