UNC looks at the whole student, but in the end you really do need the numbers too. I was admitted OOS at UVA w/likely letter, got into Michigan EA, and received honors/scholarship at UCLA, but was deferred and then waitlisted at UNC. Really couldn't have done more EC-wise (participated in internat'l competitions, captain tons of teams, several club officer positions, etc), was first from my hs to ever apply, and graduated top-1% of my class...SAT just a taaddd bit too low (~2100).
I think it's really a crapshoot. Sometimes it works out, sometimes it doesn't. But don't lose hope on your GPA, I seem to remember a few people on here last year getting in with similar stats. Just really try and make yourself unique. Why should they admit you over someone with a 4.3? That's the question you should answer for them (though outright stating it would be a little arrogant, so don't do that lol). Good luck, UNC is a great school and I'm sure you'd love it!