flexipay 9mth 0% is for all pbb cards
flexipay 12mth 0% is for pbb quantum cards only

come to think of it, is quantum card eligible for 9mth 0% flexipay as well?  nevertheless, 12mth 0% is still good, just treat it as pseudo-BT to own card 

yes. call is better. sms, never tried. i prefer to talk to CS.

swipe from merchant, make sure amount is min for the flexipay. wait till it get posted into your card, usually +1 to +3 days. then call CS to convert to Flexipay.

be mindful that you're not near your statement date. once the transaction got posted and statement-ed, you cant convert it anymore. better that you swipe after statement date.

Instalment got 1x VIP points (for Quantum)

P/S : I only hold Quantum, others I cannot clarify

so far yes, have been extended continuously, ever since i gotten my pbb card in 2016.

i guess extension news would come next week or so.

so far that i noticed 

the 12mth 0% Flexipay was introduced during Quantum launch. more like a card's benefits than a generic Flexipay offer for all cards.

Apply additional card 1st before cancellation.

better apply quantum cards first before cancel other cards
cancel other cards only after you quantum cards approved

check PBB instead of RP