Rome/Venice for sure, time for Pisa/Lucca?

I just got back from Rome, and your plan for Day 7 is pretty full. You can take a great 3+hour guided tour of Roman Forum and Colosseum. The Pantheon was closed when we were there. You can walk one day past the Colosseum, then Spanish Steps, Trevi Fountain, and other sites in Rome. There are some nice Piazza's in Rome, the one near the Pantheon, de Novana? Not sure spelling, is really nice to walk around and spend some time there. There was no signs outside why the Pantheon was closed that day. It was about 5 days after Good Friday.

In Venice - stay on Venice Island and definitely not Mestre or Guidecca or the Lido or any other place! I didn't prepare well for my first trip and wasted a lot of boring time commuting back and forth from Mestre.

spending time in Lucca is always worth it. and stopping in Pisa on the way is what we did, and that was sufficient.

agree that day 7 in Rome might be doing too much.

We spent several hours at Forum and colosseum, using rick steves audio tour. Pantheon and Trevi Fountain are close together. We enjoyed stopping in at several smaller churches. so beautiful. Our apartment was across the alley way from a small church with a Michelangelo.

Sounds like you are going to St Peter's Square, but not the Vatican? That took a half day.

Piazza Navona was nice. We went to a local farmer's market. Frankly, I just like walking around a city.

In Venice, we went across the water to this museum, which was quite cool. We also had the vaporetto pass, and enjoyed seeing the city from the water. much cheaper than gondola and you could hop on and hop off as you liked.

I decided to cut out Pisa/Lucca and just do Venice and Rome, this will reduce the amount of travel and I was able to add some more time to London and Paris where we will be prior to Italy.

You can book a timed entry to San Marco Basilica here:
https://basilicasanmarco.insidecom.it/en/attractions-in-veneto/tickets/skip-the-line-saint-marks-basilica/#choose

You all might enjoy the Secret Itinerary Tour of Doges- after the tour you are free to visit Place for as long as you like
https://palazzoducale.visitmuve.it/en/pianifica-la-tua-visita/special-itineraries/secret-itineraries-tour/

We did a timed entry at San Marco just after they opened then did the Secret Itinerary tour at 11ish I think.
Then get as far away from San Marco Plaza as you can- wander and get lost.

Get a vaporetto pass for length of stay- it is well worth the money.
Day 3 consider heading out to Burano/Murano. Your vaporetto pass will cover this trip

Rome- day 7 seems too full. Pantheon won't take a lot of time and Trevi is just a walk by but the Colosseum sights take several hours