15 nights in spain - final help with itinerary for just a few of the nights

Hi,
Barcelona - Granada is a long travel day, so I would spend the night of the 28th in Granada too - there's more to Granada than just the Alhambra.
That leaves the 29th, when you can sleep in Ronda. The town is charming but small, a few hours' visit will do. The next day, you can drive to Seville through 1-2 hill towns (e.g. Grazalema + Arcos de la Frontera or Grazalema + Zahara de la Sierra), which, again, are beautiful but quick to visit (Arcos is slightly larger than the other two).
I have mixed feelings about Cadiz. The old town, surrounded by the ocean, is a beautiful sight, but once inside, to me it's just not quite as memorable as other places in Andalucia. Now, for full transparency, I've only been once, and it's been a while, so others might differ. I'd rather spend two full days in Sevilla + Cordoba day trip.

I agree with balso. I enjoyed a recent visit to Cadiz, but you don't have a lot of time, and I suggest spending that time in Seville/Cordoba. Given all the inland destinations you want to see, I feel as if including a stop on the coast is going to take you out of your way and cost time you don't really have. For me it would come down to the white villages or the coast, and I'd choose the inland villages.

I presume you are flying between Barcelona and Granada. I think you'll find 27th and 28th rushed. I would add another night to Granada and take it off Ronda.

Rather than doing a day-trip to Cadiz from Sevilla, on 30th you could drive from Ronda to Cadiz and then drive onto Sevilla (both legs are fairly short drives). That would give you at least half a day in Cadiz. Though this may not be practical depending on when your hire car company closes in Sevilla.

But, I am biased - personally, I think Cadiz is delightful and I'm fairly indifferent to Ronda (nice bridges, though not much else; leaving aside Cadiz, Cordoba is a better option for a 1 or 2 night stay in my opinion).

I don't think you have enough time to take in the coast, apart from Cadiz, without a radical re-plan or entirely dropping Ronda.

I would try to stay at least one night in Cordoba.

It's a wonderful city that truly comes alive in the evening, when families paseo across the Roman Bridge. Plus, there are wonderful dining options and untouched neighborhoods within walking distance.

Thank you for your input. So would it make sense (since the southern coast viewing is important to my husband ) to go from Granada to Mallaga (or another southern smaller town) and stay for two nights - 9/28-30 and then on the way to Seville spend the day in Ronda (instead of spending the night there)?

When we arrive in Seville, we would assess whether or not we want to take the time for Cadiz. We def want to do a day trip to Cordoba. Also we will take an am flight to Granada and are fine with staying there just one night.

Thank you

We loved the Granada - Ronda - Arcos driving route although we did it in a slightly different order. Our route stayed in the hill country since we would have spent most of our time getting to the coast and back to Ronda. If you like to "explore" and not "feel rushed" drive from Granada to Cordoba - spend half day there and a night to see the Great Mosque/Cathedral (better to me than the Alhambra) and then train down to Sevilla and perhaps a day trip to Cadiz. Then fast train back to Madrid.