In November, I will be flying on CX845 JFK-HKG in J, arriving 5:40 am. I am ticketed to continue on to HKT on KA214, HKG-HKT also in J, departing at 2:45 pm, so I have a ~9 hour layover.

This ticket has already been purchased (award ticket), but plans have changed and I will now be flying on a separate ticket on Thai Air Asia 516 HKG-CNX (in Y), departing at 10:35 am. Putting aside the risk of separate tickets, and assuming an on-time arrival into HKG, I'm trying to figure out what my best option is for using lounges in HKG. To make life easy, I will be carrying on, so no checked luggage.

One option would be to arrive HKG and proceed to The Arrivals Lounge. Access to that lounge appears to require a 4+ hour connection, so I should be eligible for this and claim that I am going into HKG during my ticketed 9 hour layover...then simply check in with Air Asia as a local departing passenger. But since the other CX lounges (Wing/Bridge/Cabin) sound nicer, I'm wondering if I can proceed as a Transit passenger, and use these lounges without exiting Arrivals.

Essentially, I think the question comes down to the layout of the terminal, and whether the departures area for the CX flight HKG-HKT and Air Asia flight HKG-CNX are connected. If so, I believe that upon arrival from JFK, I could proceed as a transit passenger and use the HKG-HKT boarding pass (in J) to access the lounges, and then simply proceed to the departure gate for Air Asia (I'll have to figure out how to get a boarding pass, but likely could print one through online check-in at a CX lounge).

Can anyone advise on the terminal layout of HKG and whether I can easily use the CX lounges prior to the Air Asia flight?

As a separate question, are there any issues of essentially throw-away ticketing the HKG-HKT segment (i.e. since according to my JFK-HKG-HKT ticket, I'm still hanging out somewhere in HKG)?