the area around the pilot light is sealed with a metal plate and a small piece of glass for viewing the pilot light.What exactly does the thermcoupler turn off if it doesn't sense heat?

You could still park it in precious metal investments with the IRA until you decide what you can do with it.

Another house had a beige tub, but the beige was chipped off in several large places right down to the bare metal.

It's old, needs to be painted, a metal pitched roof over it and looks bad.

About 6 mo ago I paid $800 for an Armstrong furnace and $275 for coils at Locke supply Co.

(and please dont advise to replace it just in case, which I may do with a metal door, I want to know if I am required to.)

We were rehabbing an old home & found that the old narrow metal electrical boxes used in the '70's were shorting out newer/larger switches/outlets.

Also, since he started the work, the expenses have been minor so far (lead encapsulation paint, metal trim coverings for inside windows, tools to do it, etc.)  

It is to protect your heat exchanger and evaporator coil.

Make sure there is good ventilation because anyone breathing the fumes in for a longer time will be subject to brain damage.Once you got all your safety gear, get a metal bucket you can pour the stripper in and a natural bristle brush.