Agreed! I guess I should consider myself lucky - I had almost a full day invested which isn't too bad. I've spent days nailing down issues before as well and was settling in to thinking I was in for another multi-day project (interspersed between work, honey do's, kids, and 1,000 other things). You guys saved me a boatload of time and frustration no doubt. If this was an actual in-person forum thing - it would be a round of drinks on me (or at least a coffee).
Those hum X units seldom work.
The correct way to solve your problem is the right way.
The problem with your current plan is that it is not safe at all.
At the moment your only ground is now the cable system ground. From what you have discovered this ground is highly suspect and is obviously a high resistance ground.
Not only that, but if your Outlaw should have a short to ground (this can and does happen), then the path to ground is then going to be up through your cables connecting it to your receiver, your receiver case, and all the way back through your whole cable system, to a suspect ground. If you did not understand this the first time then read it again.
Now, I am not clear on the grounding system of your cable system. Where possible the cable from your company should enter at a point close to your electric panel.
Code requires that it be bonded to the panel ground by stout copper cable. The panel should be strongly bonded to your house ground.
Now here is where codes vary. Some jurisdictions insist on grounding to water pipes AND an external house ground. I don't like this practice as it is a set up for ground loops. In my new residence code requires that the house ground be at entry of the water service. This is very good practice in my view. At my former residence it was the former. In order to prevent trouble I had to sink three large 6' rods, tied together and stoutly bonded to the electric panel. The house was on sandy soil and I had to keep watering the grounds, and make sure the ground was saturated before freeze up.
Finally I should point out that designing trouble free ground planes is a skill and art form.
As this residence as it was being built, I made sure that all ground led back directly to the water entry. In other words the whole house grounding system was designed and built as a classic "Star cluster" grounding system. The main panel is in the studio chase, and all rack grounds bonded and then to the panel. I have a nice quiet system.
In your case I need to know more, and preferably with pictures, to sort this out. We have to sort this, as your current plan is not acceptable.
All bonding the Outlaw to the receiver would do, is just provide another path for current to go back to the receiver other than the connecting cables. This could actually also set up another ground loop, and would if the cable screens have a significantly different resistance to your grounding cable.
At the forefront on this you need to keep this fact in mind, that ground loops are always caused by resistances between grounds. So ground plane designs are best thought of a spokes of a wheel, and to avoid circuitous ground paths. The latter are an invitation to loops and resulting hum.