Thank you for your clear and systematic listing of your experience.
Like you, I am not diabetic but about two years ago, started having numbness, mostly on the toes of the left foot which has spread to the forefoot and pretty much the same on the right foot.
There is a little tingling at times and a very rare pain which dissipates in short order.
A CT scan showed spinal stenosis but an EMG showed no connection or causality between those.
Special blood analyses for heavy metals came back normal.
I have been on statins for many years; also on Protonix for GERD.
I also take flecainide for Afib. I had a coronary ablation in March.
We walk one to 1.5 miles most mornings which doesn't seem to be a problem. In fact my feet are better when I am active. Sometimes, when lying down, they can feel like cardboard.
I will start physical therapy next week. Not sure how that will help other than functionality, strengthening, balance, etc.
You didn't say how old you are. I will be 73 next week.
Wishing you all the best with this journey.