We are considering catching an early Circumvesuviana train in Sorrento to Pompeii (probably around 7:30 for about 40 mins) to get there when it opens at 8:30. Then Spend Rick's recommended three hours at Pompeii, catch another Circumvesuviana to Naples (another 40 minutes), catch a regular train to Rome Termini (about 1:15) and catch the Leonardo express train to Fiumicino (about 30 mins) to catch a 5:40 afternoon flight to Santorini on Aegean Airlines. I think both the airport and Aegean Airlines recommend arrival at the airport two hours in advance, so we want to get there by 3:40.
So all my Pompei touring and train travel time totals about six hours not including connection time. If I started at 7:30 and wanted to arrive for check in at the airport by 3:40pm I would have a total of two hours to buy the tickets and make all the connections. Is this way too much to try to do in the time that I have?