Don't worry about the card being issued by CIMB or by XXX bank. Merchants on the entire planet earth don't care if your card is Visa Infinite or Classic as long as the transaction can go thru. What you will experience in US is that the merchant will ask for your ID, so bring along some kind of ID with you, i.e. Passport. And they will ask you debit or credit, just answer credit.

by the way, do call your credit card Customer Service to inform them the period you be in US.

Unfortunately you don;t get interest back if you overpay... wouldn't recommend overpaying your CC.

Surprisingly CIMB did accept my World and Infinite application eventhough I didn't meet the income requirement. Just that I had to submit a lot more documents (like a normal card application) instead of just the latest salary slip. Still worth it. Applied at Sunway Pyramid for the 1 hour approval and the staffs are very helpful.

Why would one want to pay extra to their credit card? I don't see any reason why.
What my family members does is that we pay our credit cards on the last few days before the statement is due. Especially if the statement is due in the beginning of the month, we pay after the end of the month to get the interest in our saving account before paying the credit card bills off. But CIMB all due on the 31st I think. Whole point of having a credit card is to be able to make purchases on credit no? lol