"If I put in "foreign" as my current residence state, is it still ok to have NC as my "mailing address"?"
Yes.
Does this mean I will need to file NC?
Personally, I wouldn't. In actual fact you are not an NC resident and you have no NC-source income, and thus you have no legal obligation to file in NC. If NC questions you at some later point, then you can explain what happened.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
