If you have another card that allows you FREE entry to KLIA PPL, then use this said card together with the Alliance Plat to get FREE entry for you and your mum.

I hold CB PM Amex, and yes it does have unlimited access to PPL KLIA (Didn't get to use it this time though, got to the airport too late  )

The duty free with 15% off where I bought my liquor is at the baggage collection area in KLIA , not sure which company it is but shows up on statement as "DFZ Sepang", also not sure if they have in LCCT as not used that recently.

And as previous poster mentioned - Free taxi ride home with 3 international swipes which is a good deal - there's no minimum transaction limit either as far as I know. The 3 receipts I provided the other day when using this were only for 30-40 EUR in total between the 3.

BTW, midnight charge still needs to be paid and isn't covered by the free ride home  but still saves me around RM100 getting home from the airport so can't complain