actually the scb justone will be relaunch but dunno when

If the technical issue is unsolved, reissue of this product will forever be postponed to an infinite date.
I also wish to apply for a supp card after my existing card reached the max rebate limit. However, the issuance of new Just1 card is suspended, including supplementary cards.
Yes, it is not advisable to use SCB Just1 to purchase air tickets. Sometimes the cc gives you lots of direct benefits, it would make adjustment and omit other things. For instance, Amex Gold cc gives 5x points for certain transactions, but it also does not provide travel insurance. 

i have made so many calls to the cs regarding my scb justone can't even change pin, check balance, withdraw so they say they send me a second justone card which keep on being retained in the atm when i do the same so now they send me a third justone card and i am crossing fingers that it work otherwise i have given up hope on this technical issue

I dont think so. For me personally, I used my credit card a few times liao, and never once encounter any problem. I bought something at China airport few years ago with SBB mastercard, and they just called me to clarify instantly after the payment went through. Then I bought something in Thailand airport, and the same thing happen with another bank. I didnt even call to advise them Im travelling.

However, I do really prefer Citibank. Not only the rebate is good, I like how they handled internet transaction. Other banks that I tried always ask for verification like mother name, ic, birthdate. Some even need to create a pin. With Citibank card, all you need is the 3 digit CVV at the back of the card and it went through instantly.