*face-palm*
Can you please try actually reading REAL HISTORY. Like go to the library and read a history book of Spain in the dark ages? It might help you understand more than the little you do.
Mosarabic was actually not that different from the other Iberian romance languages. It just had some Arabic loan words, just as Castillian (Spanish) does so today (they were probably inherited from mosarabic). The upper classes spoke Arabic fluently, but we don't know a whole lot about the common language of Andalusia before the reconquest, just that it had "some" (we don't actually know exactly how much) Arabic influence, so we call it mosarabic. However, I can understand if the term Mosarabic is confusing, because it does sound weird in relation to what it really is.
in the 1000's, the caliphate of Cordoba was losing control and breaking down, so it invited the Almoravids (a quite jihadist Berber dyinsity of the Maghreb) to help restore order. However, just like (sort of) what happened when the Celts of Britannia invited the Saxons, the Almoravids took control themselves, significantly reversing the reconquesta for the time being, but ruling with an iron fist. It made most of the Andalusians very distrustful of the Maghrebis. And then ittl, it happens again, remember the bit about the hammer of al-alandus? That guy with his "i get to rule Andalusia, bro keeps north Africa" diverted the culture of Andalusia away from the Maghreb and towards Europe for good. (some of this is guessing, could somebody confirm this?)