Hey, can anybody give me some advice on how I should fill this rack in?

My purpose in building this is mainly to use as a sound processor for my other more standard synth.

If I have two sequencers, do I need two timetables? I suppose the two sequencers can be synchronized I guess with the CLK input?
Even though there is a VCA in the Synth Box, is another individual VCA of any real use?
I think you can use one to change the envelope of the wave, but then on the way to final audio amplification the other VCA would probably make the sound better?

I know Pittsburgh Modular made other sound effects modules, but they are not on modular grid.
1. VILFO or voltage influenced low frequency oscillator
2. VC Bend
3. Generator and Genxpander
4. Dual Ring Modulator

The Phase Shifter was there, but I didn't think that a very good effect to have within the synth since it mostly seemed like an outboard type of effect. But maybe it would be good there.