Yes unfortunately you do. In fact, you have to pay around 2-3 thousand more dollars than the overall cost spent on the credit card.
YES
no not responsible, only if you are a co-signer/joint account holder
ia an additional credit card holder liable for the whole debt of the credit card account
NO . Merchants who accept credit cards CANNOT set their own requirements for assuring that a person has authorization to use the card being submitted. Any Merchant in the US CANNOT ask for an I.D he...