I refer you to the stickies section. PN can be definitively diagnosed.

To answer your questions, being 50 pounds overweight will stress your body, and could put pressure on your nerves. One pound of weight puts 4 pounds of stress on your knees, just like it says in the commercial. However, any diet should be supervised, especially if you suspect PN, as nutritional deficiencies can exacerbate and even cause PN.

I am not sure what 'foot therapies' are being suggested, but a cause for PN should be looked for before any therapy is attempted... It is important to find out if you have PN and then what is causing the PN...and what kind of PN it is, as there are more than one kind of PN, some treatable, some not.

You have to try over the counter remedies out on your own, but, if some one is 'selling' or 'hawking' cures, be wary.

Orthotics are sometimes suggested to correct gait, which can cause all kinds of pain, all over, hips, back etc. Given you have had plantar fascitis, I would think that orthotics would have been suggested.

Stay off treadmills. If you want to exercise, walk on a flat surface, preferably one with a little give, or swim....after you are cleared by your physician.

A pinched nerve may not show on anything, as pinched nerve is a very lay person diagnosis....it isn't a clinical diagnosis. If you want PN ruled out, have an epidermal nerve fiber density test (skin biopsy) test. It is the only true way to find small fiber neuropathy when other tests are normal. (I sound like a preacher.)

PN, especially distal, burning, is worse at night.

You are right to question the diagnosis. Check out the LizaJane spread sheets and all the other resources in the stickies thread. Learn all you can about PN. Your neurologist is only as good as the facility he/she is affiliated with.

Good luck with your journey to diagnosis, and treatment.