Boiled a stainless steel pot dry, safe to eat food from the episode

Yes it is completely safe. Microwaves do not linger in food. The microwaves stop as soon as your microwave stops.

A microwave is just an electromagnetic wave similar to a radio wave, but at a higher frequency. It works by exciting molecules, particularly water, in the food and giving those molecules some of its energy as heat.

Microwaves do not alter the structure or composition of molecules or atoms directly, which is what happens with ionizing radiation (gamma rays, x-rays, and UV-rays). You could cook your food with gamma rays, but you would ionize many of the particles making them radioactive.

-- Hair is a protein mostly keratin

Keratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails.

There's nothing special about it as a protein, so as long as it doesn't wrap around your tonsils and get stuck in your throat, or contain dyes, hairspray etc. it's safe to eat. However, the long stringy nature of the stuff can cause problems if you eat too much of it.