basque country includes 3 non-basque regions. divide it up into two territories? asturias-cantabria (west) and basque country-navarre (east)?
central spain as west central spain? some regions are in the west of spain and not the center.
catalonia: it is the region you named barcelona. it is not a region that includes valencia and the islands.
http://en.wikipedia.org/wiki/Ferdinand_II_of_Aragon. when spain unified under los reyes catolicos, ferdinand ruled over aragon, catalonia, valencia, and many mediterranean islands. calling your catalonia bonus eastern spain would be better i think.