The payer is the bank or company that is paying you the interest. You don't enter the payer's address for those forms.
Investment income such as dividends and interest are treated as income by the states. They each have their own laws on the taxability. You will enter your form 1099 information to match your forms. TurboTax will transfer the information you enter to the state forms according to your residency information entered in the "My Info" section.