I like the idea!

Unfortunately, unless I am missing something, you don't have enough CV utilities for attenuating, inverting and mixing your CV signals. Maths, sure, all well and good, but for the number of modulation sources in there I would say you need at least a couple of extra CV processing modules - say something like MI Blinds.

You're almost certainly going to become very frustrated very quickly without these!

If this doesn't make sense to you and you don't understand why you absolutely need these kinds of utilities, please say so and I am sure someone, possibly myself, will point you in the right direction :)