Part 1 of a 12-day visit to Spain

We started our trip to Spain in Madrid with a 3 day visit--taking along our 10 year old granddaughter. There is so many important sights to see there.
Then we took a bus down to Granada and rented an apartment for 3 days 1/2 mile down the hill from Alhambra Palace. We got around by bus, and pretty much just enjoyed the neighborhood with the locals.
Then we flew on a budget airline over to Barcelona where we spent 4 days in an apartment. Needless to say, it's quite a place. We hit the big sights there including the zoo, and it's the only beach our granddaughter has ever been to as of now.
We took the extremely fast train to Paris from Barcelona.

We found Spain to be very reasonably priced especially in comparison with London, Paris and some of the other major European cities. The Spanish people are extremely beautiful too. Spain is a quite large country--bigger than most people realize.

We have been to a few of the coastal cities along the Med--including Malaga. That city is beyond congested with dozens and dozens of high rise condos--I assume are owned by the British. The traffic was so bad that we'll never return there. There are so many other places in Spain to visit inland that are much more enjoyable to see. Madrid and Barcelona are well worth spending more time there.

If renting a car do not drop it off in Madrid. Train travel is excellent in Spain so take advantage of it. If you need a car for hard to get to places rent it in that region only. Especially since there's a direct train from Granada to Madrid: https://www.renfe.com/es/en.
Traveling from Malaga to Tangier is not a day trip. It takes 2h to drive from Malaga to Tarifa / Algeciras and the ferry takes 1h from Tarifa / Algeciras to Tangier. Because it takes 3h to travel from Malaga to Tangier one way skip it; very few people like Tangier anyway. To appreciate Morocco, you need to take a bus from Tangier to Chefchaouen and spend two nights.
Ferry tickets are time specific just like the trains and buses: https://www.directferries.com/global/index.html. As far as getting around Tangier: https://en.wikivoyage.org/wiki/Tangier. The same with Gibraltar: https://en.wikivoyage.org/wiki/Gibraltar.

If you go to Madrid, do a day trip to Toledo.

I have been to Morocco twice and enjoyed it, but I would advise skipping Tangier. It is not worth your time to visit.

Have you been to Seville, it is fantastic.

Having been to all the places you hope to visit except Madrid (will be there on 9/8!), these are my thoughts (will try to keep your trip parts 1 and 2 separate). The “must see” sights in Spain, for us so far, are the Mezquita in Cordoba and La Sagrada Familia in Barcelona. A highlight of our Andalucia road trip last year was walking the El Caminito del Rey. We were not fans of Ronda…way too crowded and touristy. But, El Caminito del Rey could be a day trip from Malaga or Ronda could be a quick stop after the walk. We enjoyed Malaga but would suggest taking a day from there and add it on to Seville to use for a day trip to Cordoba. Am not sure you can do all you’d like at Gibraltar on a day trip. We had hoped to go to the top of the Rock then have high tea in the city but only made it up to the Rock. Granted, there was a bus strike the day we were there but, even so, I think doing both was optimistic. But, if going to the top of the Rock is a priority, go for it. We parked at La Linea and took the bus to the cable car. Had no problems with leaving luggage in the rental car. FYI, take the warnings about the monkeys up top seriously. They are quite aggressive and can be scary. The Alhambra is jaw dropping from a distance but extremely crowded on site. It became tedious for us so I would expect more so for kids. We always rent a car and self-drive so never worry about schedules or getting to rail/bus stations. Accommodation suggestion: Icon Malabar in Malaga.

PS - Morocco is worthy of a dedicated trip. As an over scheduler myself, I don’t believe you have the time to get there with this itinerary.