Hi we are going to Italy for 4 weeks in Sept – Oct. I have been before but my partner and father have not.
Rough ideas at moment.

Day 1 Fly into Rome arrive early morning have whole day and spend night there.

Day 2 Early Morning Train to Naples. See Herculaneum and then travel on overnight ferry to Aeolian Islands. (This is where my dad’s family are from and the only place he requested to see on the trip)

Days 3-5 Spend time in Aeolian Islands 2 nights . On 3 rd night catch overnight Ferry back to Naples. So have 3 whole days there.

Days 6-8 In Sorrento. Plan to go to Capri and day trip to Amalfi coast.

Days 9-12 Rome. Is this too much time or can I save a day here.

Days 13-15 Train to Venice stay 3 nights.

Days 16 18 Florence Tuscany. Where is best place to base ourselves.

Days 19-21 Cinque Terre for 3 nights.

Day 23 Travel to Milan overnight there.

Day 24-27 Lakes area not sure where yet. 3 nights

Day 28 Back to Milan. Overnight there

Day 29 Fly home for a rest.

Any advice will be greatly appreciated. If I had to get rid of anything probably time in Sorrento as I spent a week last trip in Positano. Loved it so have included it so Dad and partner can experience some of it.
Thanks

Looks ok a bit rushed might pare back some.

Pick up Florence on your way up to Venice.

then head for www.lucca.info Pisa then to

www.metropole.it best base to visit PortoFino

and www.cinqueterre.com from for me by ferry or train.

then train Genoa hang a right for Milan 2 hours.

50K north of MXP is www.stresa.org best for Lake Experience

Isola Bella is Awesome there stay at Regina Palace or

Grand Hotel Dino there my 2 favs...

Happy Journey,

Similarly, I'd fly straight to Sicily or Reggio Calabria and then pick up Naples/Herculaneum on the way north from Sorrento. I don't know where the ferries to the Aeolian Island leave from (I think Milazzo but there have to be others too, like Messina or Villa San Giovanni).

Take the ferry back to Campania and then spend 6 nights in one city in the Naples area.

Plan at least 1 down day per week where you sit and do nothing except watch the world go by. You will need to take a vacation from your vacation.

Some ferries reduce schedules in September for the winter. I would start in the north because of the weather and work my way south. Fly into Milan and out of Rome or Naples. That would also let you avoid staying in Rome twice. Consider ferries from Genoa, Livorno, Civitavecchia to Sicily or budget flights from various cities.
www.whichbudget.com
www.skyscanner.net

I wouldn't plan Herculaneum on day 2 as you can do it while you are in Naples and you would still be a bit jet-lagged from flying (you didn't say how old your father was). You would also need to store your luggage if you did this.

I wouldn't try to "save a day" by shortening your time in Rome. There's a ton of great stuff to see there.

For me, this would be too much moving around but this is personal preference.

I would tweak your itinerary to make it more practical in terms of routing.

I would not overnight twice in Milan. I quote enjoy the city but why check in and out of hotels there twice - instead spend two nights before heading home.

Same for Rome. Tweak your plan to stay once in Rome and I agree about not cutting your time there.

On Day 1, I'd travel to Naples and spend the night there, easing all the travel you plan for Day 2. Also, I would head from Cinque Terre straight to the lakes and put both nights in Milan together at the end of the trip.

Going to Sorrento directly is a good idea. Keep some of your luggage there and visit the Aolian Islands. Come back to Sorrento. This will avoid too much off packing and travelling with luggage.
3 days at Sorrento are perfect- 1 day Capri, 1 Day Amalfi drive, 1 day local sights or Pompeii.
Rome- Don't cut down on your time. 3-4 days are minimum you need.
Venice- 2 days are OK. You can save 1 day here.
Florence- 3 days are perfect. Yoy may cut down 1 day
Cinque terre I thought is over hyped. They are run down version of Portofino. You can skip this This is my personal opinion. My apologies to Cinque Terre Fans.
You can base yourself in Milan and make day trips to Portofino- St Margartita / Genova OR Base yourself at St. Margarita and make day trips to Cinque Terre, Portofino etc
Belagio on Lake Como is a great place in the northern part of Italy.
Your Itinerary is great and not overdone. You will love it.
Have fun...

All good advice above for improving this trip. It IS a bit much, but doable.

Keep your limited time in Rome - you could spend a month there and have great things to see and do every day of it.

Definitely set aside one day a week with nothing planned to "watch the world go by". Venice (the western Edge of Castello), Naples (Capodimonte), and Rome (Gianicolo) all lend themselves well to this - though each have other great "chill spots" as well.

In Rome, I could spend an afternoon at an outdoor table here on a charming little square on a quiet pedestrian street just luxuriating in "being there". Oh, and the food and wine are exquisite. http://www.ristorantesangallo.com/

For your Naples hotel, I can't recommend the Decumani enough.
It's a restored 1700's pallazzo smack in the middle of the best part of the historic center of Naples (right next to the Santa Chiara Church in the Spaccanapoli). Enormous rooms, 15 ft ceilings, charming as all get out, and an incredible value (about 100 Euro/night).

http://www.decumani.com/en/

Where are you on day 22?

I certainly would not spend that first night in Milan. Too much packing and unpacking already. Go straight to the Lakes and stay there until time to go to Milan to go home.

No one so far has pointed out that it takes a minimum of half a day, and probably longer, to move from one location to another, so those travel days are basically lost. The more travel days, the more time wasted.

And I absolutely agree you need some down time. I don't know your father's age and physical condition, but I would certainly be begging for a rest, myself.