lucca and florence with day trips

You're taking plenty of time in Florence and Lucca. My suggestion would be, don't do the opposite and short change yourself by doing only a day trip to the CT. CT is a hiking/outdoors place, and a day trip doesn't leave you time to savor the wonders of the CT. Assume you'll be back.

Uhm, you could take a couple of those 11 days in Florence and Lucca and carve out 2 memorable nights in the CT, and do it up right.

Siena will take a full day, easy bus trip (not train) from Florence.

forgot to mention that we are in mid sixties and definitely not hikers. At Ct, we just want to be able to maybe go from Riomaggiore to the next town via the easy trail and then train to the other towns, quick walks through the towns and then return to Riomaggiore via boat and back.
I know it's not a long time, but we know we can't do everything thoroughly.

After many trips to your itin, i suggest the following.

For CT consider seeing the villages by sea if it is calm. I believe part of the trail is again under repair. It is quite narrow and very busy w walkers during summer. Resting spots along trail are the villages u walk thru.

Florence and surrounding Tuscany warrants xtra 2 days tht you could pull from Lucca. That wy you couls tay in siena for part of your trip. It is wonderful experience and quite diff from your other visit areas. While lucca pisa is a gd visit it could be seen in 3 days. Pisa a half day visit. Imo.

I think you are on the right track, and Lucca is a great choice as a 'recharge station'
CT would be possible in a day to get a feel, but definitely start out as early as possible.
Have 2 days 'blank' in Lucca to potter about and then Pisa as a day by train.
Perhaps shorten Florence to 4 nights and stay in Siena (by train) for 2 nights.
You can take a bus from Siena to San Gimignano/Volterra.

I like your plan, except perhaps spend a night or two in Siena. You might enjoy Fiesole, just up the hill from Firenze.

I would highly recommend Cinque Terre. So relaxing. Book a room with a view of the sea. You don't have to be hikers to enjoy the experience. You can train between each of the towns or see them by boat. Spend 2-3 nights here, I don't think you'll regret it!! Stay in the "new town" section of Monterosso. There are several hotels steps from the train station--we stayed at La Spiaggia and loved it. Ask for a room with a terrace! It is an easy 5-minute walk to Old Town Monterosso, where you will find delightful small restaurants and shops. We spent 10 days in Italy last September with stays in Venice, Florence, Cinque Terre, and Rome--we loved the cities, but Cinque Terre was our overall favorite.

ralph: we are in mid sixties and definitely not hikers.

You may consider that some villages, going from the sea back to the train station are steep, so are some stretches on the paths..
...but you may always stop and enjoy a granita or a spritz Aperol...

And do not miss San Gimignano. Easy bus trip from Florence. ...with an easy connection.

For Fra Filippo Lippi and Donatello should not miss Prato