Split n Blend with volume control and phase inversion

[GrooveChampion]

A. Is it possible to add a fixed resistor to the circuit so that the signal will be 50% wet and 50% dry all the time and instead of the blend control to add a volume control that can boost/cut the dry volume? I am asking this because its basically two buffers and from what I understand, a buffer is a booster that is fixed in unity gain.

B. Is it possible to add a phase inversion switch?