Should I try to squeeze in a Cinque Terre day?

I think it is doable, because the rest of your itinerary does not look rushed. But I would only do it if you are staying overnight in one of the villages. Othewise you are just spending a day in a crowded village and leaving with all the other daytrippers. AND hiking with all of them. Personally I would not stay in La Spezia.

You could consider a night in Manarola. We stayed there and one late afternoon took the bus up to Volastra, then hiked down to Corniglia, had. a lovely sunset snack and then walked down the steps to the train and back to Manarola. This hike was very quiet with lovely views. There is also an easier hike around the village you could do in the morning before heading back to Florence

Regarding you Rome time, you are planning the busy spots. You might want to consider Testaccio instead of Trastevere for dinner. I would probably give more time to seeing more of Rome and skip Naples.

Yes! But don't do it as a day trip from Florence. Instead, go from Rome to CT; spend 3 nights in CT, then go to Florence, then Venice. May is a great time for CT. Spectacular scenery. Spend 3 nights so you can explore and relax. You can easily cut a day or 2 from Florence, and a day from Venice. Have a great trip!

IMO, I would pass on Cinque Terre unless you stay at least 2 nights, but then you would have to cut nights from the rest of your trip which already looks pretty good. We visited CT as a day trip in May, 11 years ago, from Livorno. It takes a long time to travel to and from CT. During the day, it was crowded with tourists. There was barely enough time for quick visits to 3 towns. No time for any hike.

PS. I count only 13 nights, which is only 12 full days. Keep in mind, you will lose almost half a day each time you change cities

Perfect allocation:
Rome 4 nights
Florence 3 nights
Venice and Murano (maybe even Burano) 3 nights
The above is only to see those cities.
For every day trip out of any of the above cities add 1 additional night to that city.
You have 12 total,so you can add two to the above for 2 day trips to wherever you wish.
Just know that Cinque Terre from Florence requires over 2.5 hour train journey (one way)

IMO, this trip is far too rushed and you probably won't be able to accomplish everything on the list. How are you planning to get around while you're in Italy?

With your present Itinerary, visiting the Cinque Terre is possible but it will be somewhat challenging. I know that as I've done that trip and it will be a long day (I didn't get back to Florence until about midnight). One day is not much time to see the five villages of the CT. Spending one night there is not a good idea for several reasons. One or two of the hikes may be possible, and the famous Via dell Amore would be the easiest (I believe reservations are required for that). Some of the trails may be closed to repair damage and you can check the status at this website - https://www.cinqueterre.eu.com/en/footpaths-cinqueterre . If you want to try a one day trip, I'd suggest starting in Riomaggiore and work your way north using the local trains, ending in the late afternoon in Monterosso. Have a fine meal in one of the restaurants there (Cantina di Miky is big favourite with many here), and then return to Florence in the evening.

The food is indeed good in Bologna (which is why it's been called "La Grassa" or "The Fat One"). However you can find great food in many places in Italy.

A bit more detail on your plans would be helpful.

Thank you all for your input! People seem to be split on the issue both in this forum and other forums I’ve read through.

For the person who asked for more details, we are taking trains between each location. I booked hotels that are close to the city centers.

BTW: I would not be trying to visit each village in Cinque Terre and probably wouldn’t do the entire hike. I would love to see one or two villages and can cut the hiking if needed.

Thanks!

Thank you!

Thanks for the clarification about your method of getting around. Trains are about the easiest and quickest way to get around Italy, especially the high speed versions. However one should always be prepared for unexpected delays or whatever.

As this is your first trip to Italy, have you researched the details about using trains in Italy? There are some potentially expensive caveats to be aware of when using public transit, and it's important to be aware of those to avoid hefty fines (which are often collected on the spot!). Are you planning to buy P-P tickets for each trip? In some cases you'll have one or more changes so it's a good idea to research the routes you'll be using and the specific types of trains used on those routes. If you need more specific information, post another note here.

If you want to go to Cinque Terre, do it. Especially if you like to hike. You can pick one village and hike to others while enjoying the spectacular views. It can be a day trip, but I think I like what another poster said, go from Rome, spend one night, and then move on to Florence. (You could also spend a night after Florence on the way to Venice).

Naples as a day trip is a very long day. But if you do it, Pompeii is close by and I have done Pompeii in an hour and half, for what it's worth. We thought that was better than skipping it.
Have a great trip.