I have all of the symptoms you mentioned, numbness in feet, heaviness in lower legs, balance problems, weakness, muscle atrophy in calves, but, no pain. It started in toes and slowly progressed up toward knees. For treatment I had prednisone, IVIG, plasmapherisis, and rituxin. I stopped all treatment 2 and a half years ago. It has not progressed.
The thought is, either the above treatments stopped it or it burnt itself out.
I try to exercise, but I don't feel it is possible for me to build my calf muscles back up until the nerve to those muscles regenerate. I can not dorsi flex (lift my foot upward) due to the weakness.
I am currently attempting stem cell therapy hoping it will help regenerate the damaged nerves in my lower legs.