Welcome to Nashville! I travel fairly often to Germany and many of those trips are to Berlin. Sadly, it can't be done right now in less than 2 stops. You've got to get to either MUC or FRA first, until the new Berlin airport opens anyway. (Of course, MUC is better). And BNA doesn't have any non-stops to Europe right now. My favorite at the moment is BNA - IAH -MUC - TXL, because you rarely have weather issues at IAH and it makes the overnight flight long enough to get some sleep.

From the hubs you listed, I assume you are in DL (and I'm sorry about that), but I'd choose ORD over JFK or ATL any day.

I hope you enjoy it here and at least BNA is one of the easiest airports in America!