I know what you mean, it's always been intimidating and confusing to me, haha, but I kind of love it. I think if you really limited the "improvised casting" element of the system by ramping up the penalties to do it, emphasized the use of/bumped up the number of rotes, and kept the powerlevel relatively low for PCs, it would fit the setting and discourage the insane powergaming that induces that headache for most people maybe?
And I think a familiar system would draw rather than repulse players, I feel like that's an argument that gets pushed a lot here ("I wanna use WoD 'cuz people know it!"), but I dunno. Why do you think so?