1) The following territories are considered Domestic: Puerto Rico, Guam, US Virgin Islands, Northern Mariana Islands, and American Samoa. There is no international country code for domestic mail.
2) State codes are listed here that includes these: https://pe.usps.com/text/pub28/28apb.htm
3) There are multiple ways to set up shipping like this. Sometimes when you have a large grid of options like you do it can be easier to write a custom function to return the correct shipping results using PHP and then save the result as a SESSION variable and then just refer to that SESSION value in your eCart rule.