But, could I use the Vbias going into Pin 3 on the tester image as ElectricDruid mentions in post #19?
You could.
Would this replace the 10K and diode on IC106A?
Yes
Or the 6.8K and 2.7nf connected to pin 3 of MN3007?
No, this is additional single RC filtering stage, following on from the active filter around U2A.
Is the 15PF the clock timing cap?
Yes, the 15pF on the 7555 is the clock timing cap.
As for this statement: The MN3007 datasheet suggests a pair of 100K resistors and a 3u3 cap to make a midpoint bias supply, but suggests that the lower resistor should be "adjusted for minimum distortion". On a proper bipolar supply, the situation is slightly different, but you can still create a virtual ground for this bias point alone. I do not understand this statement? Is the "lower" resistor referring to the 2.2K?
The lower resistor would be the lower of the pair of 100Ks used to make a bias voltage.
With a bipolar supply (say +/-6V) we actually have a genuine midpoint ground voltage, so there isn't usually any *need* to create a "virtual ground" on a bipolar circuit like we would on a single-supply circuit. However, in this case, we would like to be able to tweak that voltage a bit, so it makes sense to create a "virtual ground" rather than using the genuine one.
I also found this block diagram of a chorus that helped me understand where the clock, LFO were in the circuit.
Yeah, that's a good diagram to get your head around the building blocks we need for a chorus. The Rockman design is basically the same thing except that it uses a 7555+4013 flip-flop to provide the clock.