Hi guys, need some help on a redemption with MPC/Asiamiles

The outbound is fine but the inbound is on waitlist. Priority 1 and Priority 2 is available, I don't have enough miles but even if i do I don't want to pay 3 times to 4 times the miles just to redeem my flights.

I assume there a high chance that as its closer to my travel date March 6 that CX will release seats for waitlist? I assume being AA EXP and a lowly CX Silver I cannot request them to give me seats right?

What is the ticketing deadline? Is it before my outbound flight or inbound? Or treat it as 2 one way on the same ticket and once my inbound clear they will refund the extra miles I pay?

What happen if it turn out seats for another class open up and I decided to change. Does it get treated as 2 one way ticket?

Last question I read some of the post and it was mention a few times that sometimes CX bypass the waitlist and put the seats for upgrade/redemption or partner redemption. How can I avoid this? Is there a specific number of days before my flight to call cx/mpc? I've head once its release to BAEC its difficult to get CX to clear my waitlist even if redemption is available for partners/MPC