I think this connection is doable, but want your input. Leave Chiusi 07:10 to Rome via train 1 hour 14 min. Rome termini to FCO for 11:45 flight. I think this puts me in FCO about 09:30. Comments?

I wouldn't do it. Italian trains are not notoriously reliable.

Is there an earlier train or, better still, would you be averse to spending your last night in Roma instead of Chiusi?

I was hoping for a positive response.
It is not possible to stay in Rome. I may need an earlier train. Or redo the trip Tuscany first Rome second

I sympathize, but I think at bottom you really were looking for an honest response!

What's your itinerary? There may be a happy solution.

Arrive Rome April 23 for 2 nights Train to Chiusi 3 nights-- April 28th Trains as stated 7 10 to Rome Rome Termini to FCO Flight to Dublin 11;45

I would be more comfortable with an earlier train since you are trying to catch a flight. I was on a train from Rome that was over 45 mins. late arriving in Rome, not sure why as it left on time from Bari. The trains from Rome to FCO run every 20 mins or so, but you should be at FCO at least 2 hrs early to get through security. It can get really packed.

I agree--go earlier and then you have a backup in case.

earlier it is
thank you