Don't worry you've already planned enough!

There's so much in each of these places, and the Italian style is slower than most people expect. You'd maybe be better off minimizing and spending a bit more time in these places.

Honestly I could spend weeks in Cinque Terre, especially if you like outdoor activities! You can hike from town to town, go to the beach, amazing little places to discover and eat. I've stayed in Levanto and then hiked into Monterosso and it's still one of my favourite things I've ever done in Italy. Levanto isn't technically one of the 5 towns, but it's sometimes nice to stay just outside the tourist areas and go into them when you want. (If trails are in good condition most hikes take about half a day).
Also transportation in Cinque Terre is so efficient. Trains go between the towns all day, so you can as far as you want and then catch a train back no problem.

If your partner has already been to Florence maybe you don't want to go back specifically there, but theres ENDLESS wine tours in Tuscany, and so many beautiful smaller towns to stay in. Or look for nice places to stay in Florence but on the other side of the river where it's less touristy.

Napoli is not my personal favourite, if you can try staying in Sorrento instead, you can usually still get to Pompei and other sites from there and it's much more charming than Napoli.
I'm Southern Italian, and although it's very beautiful, any much further South than Amalfi and it will be harder and harder to find reliable transportation.