I took a trip through Spain hitting Madrid (3 nights), Cordaba (2 nights), Seville (3 nights), Granada (2 nights) and out of Malaga this past winer. Getting between the cities and to Malaga worked extremely well. Previously, I've been to Avila, Toledo and Barcelona on trips.
I have to agree w/ above - 6 days in Granada is waaaaaay too long. 2 nights was enough. The Alhambra was amazing... but only requires a 1/2 day. Wondering around the old town is another day, and you will have seen everything you need to.
It looks like you have 14 nights. That is a long trip... your lucky to have enough time to enjoy the majority of central Spain.
Cordoba (and almost any city) is worth more than 1 night... I hate having to worry about where I'm going the next day while I'm checking into a hotel the night before. The Mezquita in Cordoba was the most impressive site on my trip. I loved the old town as well.
Toledo is such a short trip, it is a viable day trip, but the ambiance of the city at night time is worth at least one night.
Avila is another day trip from Madrid - the city walls there are very impressive.
I think you could comfortably visit all of this if you shorten your Granada trip... and its all worth seeing.