Sugar maple and Root Girdling

[oldhouseguy]

My maple is weak on one side with lighter color leaves, and all the leaves are a bit small. I was told it was girdling, so I've excavated around the base to check it out.
I don't see any circular patterns of growth. In general there was a little too much soil and mulch covering the 2 large root flares (one side doesn't really have a strong flare).
I had one 1 1/2" root near the surface slightly girdling before heading straight out (on the weaker side, see pic) so I cut it. Did I cut it enough? Also, there is ra concave section of trunk on the healthier side of the tree. Directly under that section or trunk are some roots growing from under it and away from the trunk. I'm hesitant to cut this one shown, as it may just be a weird growth pattern and it doesn't encircle the trunk. It also may be bearing weight. Should I cut this or leave it? There is another one behind it thats quite large, and I'm not cutting that. Could the one that I already cut have been the issue all on its own? I don't want to over prune, but I'm at least trying something to save the tree.

 

[Raintree]

At this point I would cover that disaster up with mulch and walk away. Advantageous roots supporting healthy side is problematic. Severing the one small offending root is beneficial however window dressing.

 

[Brufab]

Unfortunately that tree will end up being firewood as it looks like it is dying. Better to cut sooner than later before it falls on the house or becomes more diseased and potentially spread to other trees of the same type