Seems that the added Catholic provinces are more than enough to make life for the Umayyads a little harder. I'm not sold on moving Andalusian out of the Iberian culture group, because non-Iberian Muslims are already represented by the Mashriqi culture of the majority of the ruling classes. It would only make things even harder for the few "native" Islamic dynasties such as the al-Qasi, who already have a difficult time as it is. Extending the northern Iberian cultures further south seems anachronistic (in fact even the SWMH split between Leonese and Castilian does). If anything, I'd give some more coastal provinces Catalan and one or two more provinces around Zaragoza Aragonese cultuer. Generally Mozarabs are best understood as part of the Andalusian culture, though. It would be great to represent Berbers and Sephardis somehow, but as you mentioned it's difficult to do within the confines of the majority-per-province system.