For less travel stress recommend flying onto Seville which means you do not have to handle your luggage until arriving in Seville or use a different mode of transport. This is much more efficient use of your time.
We base out of Malaga and use a car to travel throughout the area. That said we offer the following recommendations/comments:
If you are staying in old town seville having a car is a costly pain in the butt due to getting around in old town, propsensity to be given a ticket, cost of parking and timw spent from getting out of old town and to the edge of the city where your day trip actually commences (add 45 minutes from old town to edge of city one way, so you are sheeing up an hour and a half each time you seek to leave/return the city).
Consider excellent public transport options exist for day trips. Bus service is great and please doe not insult the Spaniards with any thoughts of comparison to USA bus service. Suggest using train/bus service due to less travel stress, usually much chewper than a car, you get to sit and relax while watching the countryside, etc.
From Seville you can day trip via train to Cordoba, bus/train to ronda and several other equal distance places.
We have no interest in Morocco due to "much too touristy" reviews provided by friends who have made the trip.
Four nights in Seville with day trips is time well invested.
Three nights in Granada is time well invested. You must google how to visit alhambra in order to learn about best method to obtain tickets and gain most from the visit.
Thought: we prefer to stay in apartments any time we stay in one local for a minimum of three days (more room, kitchen, usually less expense)
Fly from granada to barcelona and stay four nights.
AVE RENFE train from barcelona to madrid for remainder of the trip.
This itinerary provides a journey through four distinct geographic regions and ultures of Spain.
What time of year are you planning on making this trip?