I am not a lawyer
Speaking as someone who has done almost exactly what your wife has done (differences: I left the state because I was afraid, and that was the day we separated, I had to leave my job so I could leave the state to be safe, and my stbx is an addict), I can say that it is not considered kidnapping.
Of course, you can file for emergency custody, and ask that the judge require your wife and child to return to NC, and depending on the circumstances surrounding why she left (ie, did she do it out of spite, did she do it out of fear?) the judge may or may not order her return. In my case, the judge allowed me to stay because I went to my nearest family (which happened to be in FL), and because my stbx is an addict, and we were not safe. If there are no reasons why she “had” to leave, you have a very good chance that the judge may order their return (or at the minimum, your child’s return, but you know she’ll come back with the child if the child is required to return). Judges don’t like it when parents leave the state just because. There really has to be a good reason (like, if you are abusive, an addict, etc) for a judge to be okay with a parent moving to where visitation is hindered.
All that said, I don’t know the specifics of your case, so I cannot say how I feel about your particular case, but unless there is good reason to keep your child from you, the courts don’t like to allow things like this.
Don’t have any idea about the spousal support thing…not an issue in my case.