Paying NC Income tax as non (or part-time?) Resident

Hmm. I could use a little hand-holding here. I'm extremely confused...
 - I am a resident of WA state.. My car tabs, voting, library card and address are all there.

- That said, I work for a business out of Charlotte NC.

- I also have family in NC so I've been spending chunks of time in NC. (about 6 months this past year, in total)

 

So, question #1 is: Am I considered a non-resident or a part-time resident? I'm not sure what officially constitutes 'resident' status.

 

Question #2 is: when I file NC income tax, do I leave the total amount as-is (in the box where I select NC source - non or pt resident) and let TurboTax work it out? Or do I actually tell it that, for example, 20k was made while I was in NC and 20k was while I was in WA?

 

I've done this for several years now and I feel like I'm confused every year and do it differently every year. I'd love to get this right!