coming late to this but you might be better heading directly south from sevilla to jerez/cadiz/sanlucar...if you still want some walking, the donana national park is spectacular.
from there you could head south east along the costa de la luz and end up in malaga. i love malaga but i think 2/3 days there is enough

Ronda was nice, but I'm not sure I would spend 3 days there. It's pretty small. It's pretty for sure though.

It sounds like you have traveled a lot, why not go down to Morocco, since maybe you have not done that.