Serum potassium 5.4. doc not worried. should i get 2nd opinion? would that cause burning/freezing feet?

Potassium of 5.4: I would repeat the blood work and assess the results. You do not mention other lab values, such as creatinine, BUN and co2. If these are normal, i would agree with your physician (p). You do not have diabetes nor hypertension, so there is no obvious reason for you have significant kidney disease. See a physician about the problems in your feet. An exam of your feet is crucial to get an answer.