1. Yes. PPL at Gateway is buffet type. u can eat as much as u want.
2. Yes all 3 can enter.
3. Yes. Actually doesnt matter domestic or international flight

for all this time, i just use aeon in KLIA & KLIA2. other airport, use other card that confirmed can enter 

btw here where i found - https://www.aeoncredit.com.my/aeon-cards/ae...-visa-gold-card

go to Card Features & Benefits - 
Free Access to Plaza Premium Lounge Malaysia
Enjoy 6X Free Access to the Plaza Premium Airport Lounges for a year at KLIA & klia2 with your Principal ÆON BiG Credit Card

didnt mentioned other airport or "all Plaza Premium Lounges in Malaysia" (this is example of RHB website)

Called CS. The lady said they themselves need to submit the enquiry to PPL to check - which will take few working days.

Other wise, when I travel, can approach PPL to check, they'll have every travellers entry data

Summary for CC free access to PPL Aerotel at KLIA2:
1) AEON CC (Gold and above)
2) CIMB CC (with certificate)
3) SCB CC (World Miles and Visa Infinite)
4) Maybank Visa Infinite

Do I miss any or summary wrongly? 😀

The 2M here is referring to the Gateway PPL, not aerotel lounge.