Leonardo Express from Rome Termini to FCO airport

That sounds like the Air France flight to CDG, we did that run in May 2009. We used Romecabs.com, arranged for pickup at 5 am, they were a few minutes early as were we, it worked our great. When we got to the airport, the driver got a cart for us and loaded our luggage on to it, we did not ask him to, just part of his service. We were through security and had plenty of time for a final breakfast in Italy near our gate.

The first Leonardo Express each day departs Roma Termini at 5:52am and arrives FCO at 6:23am. Since your Rome-Paris flight is an intra-EU flight, you won't need to be there as early as for a US-bound flight. I check to see how long before departure I'm required to check-in, and then plan to arrive at the airport at least an hour before that.

Frank is correct since it is a domestic flight. 6AM would PROBABLY be fine but 5:30 would provide a little margin. At that time of morning it should be pretty quick. I would have your hotel arrange a shuttle. Last October the shuttle for two was 33E and train would have been 28E, a small difference for door to door. The cut off for checkin is 45 minutes. Notice that you have now asked this question three times and received similar answers. Is there something about our answers that is not clear? Send a PM if something needs a better explanation.

2 hours before the flight should be enough time. I also suggest romecabs.com. We used them last month, they were very reliable. The charge is E45 for a private car.

Just did this for wife this last Sunday, and Inter EU you only need an 1 1/2 to 2 hours.