All Video, The AVR is handling all channel's volume, including the Front Volume, i.e. more or less attenuation of the signal,
you do the initial setup with the AVR, ONCE, from the listening position (level adjusting front to center to rear to sub), and then you only alter the volume of them all together. Your AVR must have front pre-outs.
the HT Bypass is a PASSSIVE Input/Pass Thru, to the 'better' amp for the Front Speakers, thus it avoids other circuits in the preamp