You can take a bus or airport transfer from Malaga's airport to Estepona (note spelling) and then, on the 21st or 22nd, rent a car for the rest of your trip. That way, you won't pose a danger to yourselves or others. Though why you would want a car for this trip escapes me -- parking in these cities can be a pain, and Spain has excellent public transportation.

Cordoba, Seville, and Granada may be the best cities in Andalucia in Southern Spain. I spent 4 nights in Seville, 2 in Granada, and 2 in Cordoba. I didn't make time for anything else in Andalucia. If I was going to add other locations in Andalucia, I would probably add Malaga and Nerja. There is a town on the Mediterranean cost of Spain called Estepona. Your latest supposed itinerary will work ok. A lot of travelers overpack. I have learned to pack just two extra changes of clothes in a travel bag or gym bag, addition to any cold weather items and whatever is not clothes in a separate backpack. But I am a single man traveling solo.

Cdnyul, we are currently planning a 20 day trial to Spain, late March to mid April and am still busy planning the itinerary. I'm curious as to why you've never visited Granada in the 20 years that you've been traveling to Spain.

Twelve years, not twenty.
Primarly, for logistical reasons, our travel dates are usually finalized 48 hrs. before departure and frequently we advance our return dates.

I agree with taking the airport shuttle to Málaga. I don't agree that 'parking in the cities can be a pain'. You may recall that we always rent a car, wherever we travel. Every city in Spain has public parking garages close to the centre where you can leave your car safely. In top tourist season it's better to make a reservation but in November there will be plenty of parking spaces. When you travel by car you can stop wherever you want and discover soms gems that you won't see traveling by train. For instance, the very pretty town of Carmona on the way from Córdoba to Sevilla.