Ports were ok. some were larger, some smaller capacity. Trick would be transportation within Spain. Its railroads were not as extensive as in France or Belgium, nor did they have the same capacity per km of track. They were not in good shape after three years of Depression & war. a Allied army marching to the Pyrenees, or to Madrid would have to bring extra railway capacity. The automotive roads were not suitable for a Brit or US mechanized army either.
Best course for the Allies is to seize the region adjacent to the straits, & make sure Portugal & its Wolfram or Tungsten mines are secure. Let the Spanish settle their own differences. If the Germans choose to send Panzer divisions to Iberia thats fine, every division there is one less in Normandy Marsailles, or Italy.
Agreed on the Spanish front; I was just curious about the ports in Spanish Morocco. Were they more lightly defended than the ones in the French colonies, and were they in any sort of comparable shape?
At least the poor state of the Spanish infrastructure will slow everyone down. Combined with the partisan war that lingers on, the cross border raids with Portugal that will inevitably crop up (even if it's just Spanish partisans trying to duck in and out for safety) and Iberia looks to be a quagmire.
After the war, though, is a question. Would the reconstruction of Spain follow along the lines of Germany, Japan, or a different country? It might be interesting to see a healthy Spain come out of the war.
For an off the wall idea, what of the Canaries? Could they become something like an European Okinawa? Granted, that might not be the best way to put it, especially as that would give the US another European base to focus on. That or the Spanish Rif would be an interesting post-war result, if bases are built in those regions similarly to the ones in Germany/Italy.