3 Days in Palermo

i would say yes to one more day in palermo. the city is so chock full of amazing sites to see that a day and a half seems too short. just to name a few: san cataldo, santa caterina, la martorana, palazzo cuba, la ziza, capella palatina, and san giuseppe dei theatini. the street food at the ballaro market is not to be missed either. if you stay somewhere in the center then most of the sites i mentioned are within walking distance. palazzo cuba and and la ziza are a little further away and driving may save you some time. hope this helps.

How many nights in each? That gives me a better idea of how much time you really have.
Replace your number of days in your post with the number of nights.

Roberto- The days are actually the night count so Palermo is 3 nights, Trapani is 2 nights and so on,
With your knowledge of Italy do you think and extra day in either Ragusa or Siracusa is warranted or should I leave as is and add just the day to Palermo as alomaker suggested.
We will be continuing on the mainland for another 15 days as well but will be a relaxed food exploration and areas not seen .We have been fortunate to have been 6 times already to this wonderful country.

Since you plan to go to Cefalù while you are in Palermo, then yes, you might need an extra night in Palermo.
The rest seem ok. You might even visit Selinunte, from Trapani (or on the way to Agrigento).

You have a car, so you might also consider staying at an Agriturismo (farmhouse hotel) or small town hotel.

Thanks Roberto. Am thinking of Selinute instead Agrigento staying at an agriturismo as you suggested before going to Villa Romana.
I guess I should ask- is Valley of the Temples a must see or is Selinute just as interesting.

You can’t go wrong adding another night to Palermo. The most underrated city I’ve visited.

On the other hand, Taormina feels very short-changed for the effort. Especially if you’re trying to visit Etna. I have to say too, I have the nagging feeling like this is all a bit too much. Each stop feels like there’s a real squeeze on it. You may be better served by axing a stop, Taormina or Trapani would be my vote. Sicily can make for hard decisions.

I visited the Valley of the Temples on the go. Left the morning from Scopello, stopped a few hours along the way at the Valley. By evening I was in Avola., not far from Siracusa. Basically I covered the entire Southern coast in one day drive, including the few hours in Agrigento.

Selinunte and the Valley are similar. I visited both although in separate days. It's up to you. After a while, those temples started to look the same to me. For sure you should try to see the Temple of Segesta (closest to Erice/Trapani). Then between Selinunte and Valley of the Temples is up to you. The latter is probably more important. There is also a very important Archeological park in Siracusa which should be visited as well.

If you have time to go to Levanzo (island) or Mazara del Vallo from Trapani, those are nice towns.

while argigento is more extensive and certainly more famous (more tourists too probably) i liked segesta better for the landscape. unfortunately, i couldn't figure out a way to make a day trip on public transportation to salinunte. you are driving so that shouldn't be a problem.