I am afraid you cannot use the arrivals lounge when arriving on a medium-haul flight from VCE. You should use the departures lounge in the isthmus building, which is next to the
jetée, the building where part of the roof collapsed. It is to the left, after passport control and security, one level down. It is one of the best AF lounges and there are showers. If your flight to ATL leaves from the remote gates located in Satellite H, you could also use the lounge located there, but I have not been there yet, and it is most probably not as good as the main 2E lounge.
Regarding the connection from your arrival in 2F to departure 2E, it is simple enough. After leaving the baggage retrieval area, you just walk across, through the gallery, to the arrivals level in 2E (5mn) and take the elevator up to the departures level. No need to take a shuttle.
Enjoy your flight
.