I am taking ITA airway flight from from MIA-FCO-VCE with an 1hr 40min layover in Rome then flying out Venice with ITA, is that enough time or too risky will I have issues even if it was all purchased in one ticket ? The ticket that I purchased is all with ITA airways, none are separate wondering if anyone here has done something similar.
IF you did miss your connection, ITA has another flight 4 hours later they can put you on.
Last Fall I flew LAX-FCO and met friends that were on the MIA-FCO flight - we both arrived earlier than scheduled in Rome. As mentioned above, ITA has other flights to VCE later in the day, and since you're on a single ticket, they are responsible to get you there.
You can check the ontime performance of your flight at one of the online tracking services, such as FlightAware.
With one ticket, ITA is responsible to get you to final destination. You will have to change terminals. The MIA-FCO flight arrives at Terminal 3 and FCO-VCE departs Terminal 1.
I used ITA two months ago in August. My transition through FCO passport control was a breeze. My ITA experience was quite professional and efficient. If all goes well departing from your point of origin and you indeed have a 1 hour and 40 minute layover time then you should have plenty of time.
The MIA-FCO flight arrives at Terminal 3 and FCO-VCE departs Terminal 1.
Just to point out that it's really one gigantic building - the terminal designations are most important in the departure area, where you check in for your flight.
Your Miami flight will arrive at the E gate International [non-Schengen] wing, and from there you will have a long walk to immigration. Then another walk to the A gates for domestic flights.
But no transfer by going outside between buildings, such as at Heathrow.