I think you're actually in pretty good shape for VCAs (six VCAs for a system of this size seems fine). What you may find, though, is that you need more sound sources... unless you count filters self-oscillating, you only have one oscillator here. You don't need to add a second source immediately, but it should probably be high on your list for next steps.
You're in good shape for most other things, I think, but one thing I always like to suggest is Sloths. It would go very well here.
Finally, how are you controlling/sequencing this? MIDI? If not, then you might want some sort of sequencer module.