Apparently there are many that use ATL as their hub. It didn't get to be that large of an airport for nothing.
As for your flight leaving on time. You HOPE that it does...there are never guarantees. I fly out of SAN...possibly the best weather spot in the US(I don't take morning flights ..so fog isn't an issue)..and even we get delayed once in a while.
IMHO...you have a lot to learn.