Itinarary Venice, Cinque Terra, Amalfi Rome?

Are you hikers? If so the Cinque Terra deserves more than a day or two. Venice however deserves, and will fill up, more than 3 nights! The Amalfi coast I feel should be based out of Sorrento. From there you can do a day trip that includes Positano and Amalfi Town and another day trip to Capri. Herculeum or Pompeii would fill another day. Sorrento is a beautiful town, especially at sunset and well into the night. I always plan my day trips around returning to Sorrento (isn't there a song by that title?) sunset. If you haven't been to Rome before I'd give it another night at least.

So maybe steal from Cinque Terra and give to Venice and Rome?

You say you have been to Italy before, but you didn't say where. If you have not been to any of the cities you mentioned, I would say 3 nights Venice, 3 nights Cinque Terre, 4-5 nights Amalfi (Sorrento) and remaining in Rome.

The order seems fine, going from north to south, when weather gets cooler, makes sense. I have not gone in October, so I am not sure how Cinque Terre will be. Also, a lot of people get tired in CT after a couple of days (not me, though, I stay 5 days because I love the place!).

Building on the following...
3 nights Florence
4 nights Cinque Terre
4 nights Amalfi Coast
2 nights Rome

And looking to add night #14, then consider...
- 1 night stopover in Milan
- 1 night stopover in Verona
- 1 night extra in Venice, with a day excursion to Padova

As someone who has been to Venice 7 times, the Cinque Terre 4 times, and the Amalfi Coast 3 times, I think you have a good plan, assuming you've also had your fill of Rome since 2 nights here is not much time....

Venice can easily take 4 nights, though, on a first visit even without leaving the Laguna. (No need for side trips to Padova or Verona, although you could.) And as the A.C. is a long trip, I would encourage 5 nights there, basing as mentioned above in Sorrento. That would perhaps leave only 3 nights for the Cinque Terre, which is enough unless you are hiking addicts. As to the crowds and weather, we have gone 4 times in October and had great luck with weather. No guarantees of course. Crowds? Yes, but if you get away from the Trail #2 and are not there on a weekend, you just might survive the crowds. The evenings are blissful!

Just my two centissimi.

Thank you all for your suggestions.

We have been to Venice & Rome prior so, Cinque Terra , and Amalfi coast are new to us.

Thanks for your suggestions, I appreciate the input.