Good idea to document determination. - Particularly if you conclude you are not subject to the rule. - Not a rule requirement. See Section 2.4 of SPCC guidance document. http://www.epa.gov/emergencies/docs/oil/spcc/guidance/2_Applicability.pdf.
The age of consent is eighteen. With parental consent, parties can marry at age seventeen with the exception that if one party does not have a parent who resides in the state and one party has been a resident in Oregon for at least six months, then no permission is necessary.
Kollin is wrong about the age of consent; About 20% of the states set the age at 17, but Arizona is not one of them. Arizona is among the roughly 20% of U.S. states that places the age of consent at 18. This means that if you are under 18, you are underage and sex with you is a crime. Some states have what are called Romeo & Juliet laws or close-in-age exemptions for people who are younger than the state age of consent but are within a certain age range.