Be aware there certainly have been errors, or at least non-sequitirs, regarding the prereqs for spells published in past supplements.
Most notabley, in The Scrolls of Skelos, the spell voice of power has itself as a prerequisite. Though obviously a misprint, I like to think it was intended as a joke thwart scholars.
Others are just redundant. The prereq list for enslave lists both Magic Attack bonus +4 and ranged hypnotism. The latter itself requires MAB +5 rendering the former superfluous. Tidy it up!