2: 1% does not seem to be the bank's profit. It seems that after your bank card is overdrawn, the bank charges a handling fee according to the installment interest rate.

3. Credit card overdraft has points. As long as you pay the arrears on time, don't be overdue. If your transaction record is average for about half a year, you can apply for an increase in the amount.

4.4: Of course, I don't know about credit cards. If you save, you can pay 200,000 yuan in cash and transfer 500,000 yuan.