Gibson GSS100 Noise and Pop Issues

[Saransk]

I have a GSS100 that has had a complete cap and resistor update
Overall it works fine but has a couple of issues.
1 - Persistent hum.  May be just part of the design after I added a 3 prong AC cord.  Worse with Reverb turned up
I was thinking of adding isolated Input jacks and having a dedicated signal ground.
2 - "spitting" noise - random from the system.  No specific control or cause. Appears to be from the power amp since it occurs with either pre-amp chain.  The main Power Supply caps are new as are the ones
3 - Pops - loud., But it seems to be only with the "Rock - n - Roll" switch in the Off position.  Turning the Tremolo knob from Vibrato to Tremolo creates a very large pop.  Turning the amp off/on creates a typical "solid-state" pop.  But none of this occurs if the RnR switch is On.  It seems like there is a ground issue or "floating" voltage when the Vibrato Board is cut out of the signal path.
I've attached the schematics of the affected boards - I have the "B" model set.
Any ideas would be helpful.