If you go by that strategy, then only 2-3 states are really important.
Well yeah, basically. You need to get to ~49% nationwide to have any chance of winning anyway. If Romney's at that level, he's already won IN and NC and a lot of other places that Obama won yet underperformed his 2008 national average. Then it comes down to states that were close to the 2008 national average, such as VA, OH, CO, IA etc.
North Carolina is a totally different construction site than Indiana. The state will be close in any case.
naw man, it wouldn't any sense for Obama and Romney to be tied nationally yet also tied in NC.