Finished Klein Bottle, quality control issue, and a question

[Chrisx5x5]

Finished my Klein Bottle (from the barebones kit) and it works! Now I need to take night classes to learn how to use it though 

I took the long road when stuffing the PCB, finding what each resistor and cap was connected to on either side and measuring the resistance/capacitance between those points as a check on whether the soldering was good.
There was one SMD chip (IC9) which had a very tiny solder splash grounding out one of its pins to R67. Once I determined from the schematic that that couldn't be right, it was easy to fix. Watch out for those.

I have a couple of questions for the experts regarding the schematic:
1. Where on the big schematic are the three footswitches?
2. [probably related] Can someone help me understand what IC 2, IC4, IC6 are doing?

Cheers,
Chris