That default is what makes SR worth using, otherwise the d20 roll with make it useless. Having a base of 6-8 would make the class able to deal with spells in general in a useful manner. And mentioning the exceptions is exactly what I was getting at. "All Witch spells, except as noted here:" followed by listing only the stuff from other classes, keeping the list short and down to the essentials. This is a Witch/Fighter hybrid, so it should only have utterly needed spells from other classes in the base version of the class.