Canon VR-HF720 dim band on picture / bad sound
 

https://www.youtube.com/watch?v=mAesU8hz8PU
The video linked above shows just about everything you need to know.
I've never done repairs on a VCR before, every deck I've had previously just worked...

Have you tried other tapes? Are the heads clean?

I tried a commercially duplicated tape, sound was better but the noise faded in and out & picture had light/dim bands.
I cleaned heads with paper & alcohol. Noticed some dark residue in one of the grooves on the drum

Is there a tracking control? Do you have an oscilloscope?

I'll have to look. I own a Tektronix 422, 15 MHz scope

Yes this deck does have tracking controls. Able to clear up sound but it appears right channel is louder than left on VU. Haven't confirmed as monitor is mono only. Bands still appear over picture.

This Canon deck is a rebadged Panasonic NV-H70PX / AG-1810.
Allegedly, similar models have issues tracking non-Panasonic tapes.

I'm not sure if 15MHz is fast enough to check the RF envelope or not.

It should be. The highest luminance FM carrier frequency on the tape (for a white signal) is 4.4 Mhz, and even including sidebands for high frequency detail should be well under 10 Mhz.