I like that schedule a lot. I do think you've got more time than needed in Ronda. Three nights should really be fine. Places that could use more time: Seville (very large city--much more to see here than in Malaga) and Madrid (because of the wealth of day trips). Toledo's not the only great side trip from Madrid (though it is my favorite), but not getting to Segovia, Cuenca and Alcala de Henares this year will give you a reason to return.
You may run into some closures on May 1. The year I traveled to that area, sight operating hours were often adjusted at the beginning of May, so be aware that info you find online in March or early April may no longer be accurate by May 1.
I don't see a need for the car after you get to Malaga. Maybe you'll use it to go out in the countryside when you're in Granada?? However, I'm not a rent-a-car-in-Europe person; others may have a different perspective.
International Museum Day is usually on or around May 18; some areas and sights use a different date. On this day many museums will be open late and/or free. On the other hand, the week before IMD may see sections of some museums closed as new temporary exhibits are installed.
You have enough time in Granada that it could be worthwhile to buy the Dobla de Oro ticket to the Alhambra (an extra 8 euros) or even a 48- or 72-hour Granada Card. However, most entry fees in Granada are quite modest, so you won't necessarily save much money with one of the more expensive options.
Here's a list of sights in Malaga I put together before my 2019 trip to Andalucia. Check websites for current days and hours of operation. Many places used to have a few free hours each week.
- Alcazaba y Gibralfaro: Great views as you walk up through the gardens. Archaeological museum has good Moorish ceramics and fine Mudejar ceilings. See video at Visitor Center first. Probably open daily.
- Paseo del Parque: Seaside promenade, tree-shaded and cool. Tiled benches.
- Catedral Santa Iglesia: A must. Late Renaissance interior. Spectacular choir stalls, marble sculptures behind altar. Gardens at back, and El Sagrario church with magnificent plateresque altar and ornate Isabelline-Gothic portal. Museum probably open only Mon-Sat.
- Museo de Malaga, Palacio de la Aduana: Two sections: art and archaeology. Probably closed Monday.
- Picasso Museum, Palacio Buenavista: 16C palace. Remnants of Phoenician wall in basement. Cafe. Probably open daily.
- Coleccion Museo Ruso San Petersburgo / Malaga: 15C/20C art. Probably closed Monday.
- Casa Natal y Fundacion Picasso. Supposedly has a seasonal gallery downstairs and a permanent collection with drawings, photos, ceramics upstairs. However, I (who never skip an art museum) found this basically a waste of time. Probably still open daily.
- El Centro de Arte Contemporaneo (CAC): Permanent and temporary exhibitions. Probably closed Monday. May still be free.
- Museo Jorge Rando: Expressionist art. Was free and closed Sunday in 2018.
- Museo del Vidrio y Cristal de Malaga: Very good glass collection in restored 18C house. 1-hour guided tour, non-scheduled. Probably closed Monday. €4.
- Museo Revello de Toro: Art museum in interesting building; heavy on protraits. Probably closed Monday.
- Museo Unicaja de Artes y Costumbres Populares: Ethnographic museum. Probably closed Sunday.
- Museo Carmen Thyssen: Fine 13C-20C Spanish art. Probably closed Monday.
- Centre Pompidou: Impressive 20C/21C art. Probably closed Tuesday.
- Flea MKT on Sunday.
Outside the center of town:
- Finca de la Concepcion, Carretera de las Pedrizas km. 166, 4 miles N. of Malaga: Botanical garden with palms and exotics. Probably closed Monday.
- Scenic RR route to Fuengirola. 45 minutes with stunning views of Mediterranean from above.
