Have no opinion on Campbell taking the UNC job. But, IMO that is a very attractive job as the UNC President & AD is going to give any new coach a lot of resources to succeed as UNC positions themselves for a jump to Big10 or SEC when there is another round of realignment.
Even if the next round of realignment is 5 years away, within the ACC there are only a couple other ACC schools that have similar financial resources going into an era when athletes are going to get paid. And one of those schools, FSU, is a disaster.
Regarding the 12 team playoff, the ACC might be the easiest path because the competitive balance in the ACC is not as good as Big12.
Lastly, Chapel Hill wouldn't be a bad area to live and should be a relatively easy area to recruit to as North Carolina and neighboring states produce a lot of football talent.