Yes, my grandparents had a potbelly stove that they used for heat. A coal tripple was about a quarter of a mile from our house and we could walk down the railroad tracks and collect a bucket full.

Yes, I have seen and lit it several times.

I was often in charge of lighting the grill when I lived at home with my parents, we used a hot air gun to light the grill, and it worked really well, we never used lighter fluid, just hot air, and during the process you easily see flames comming up from the burning coal.

Failing that, I used to be an active member of a herritage railroad with steam trains, looking into the firebox of a steam enging you clearly see the coals burning.

Why would you not do that?

Yes, growing up. Even saw it get made, though I don't remember much. Perks of being part of the peasantry I suppose...

We had to make it ourselves because it was too expensive to buy. Used a little bit for everything, cooking, heating, making booze.
Then things changed, laws passed, gas became cheaper and coal-making was forgotten because it was too much work for too little gain.

What's the difference?

Yes. Used to build and install coal boilers for hot water heating systems.

Yep. When I was young, we had a stove in my house for heat that burnt coal or wood. We mostly burnt coal in it.

Yes, I have coal furnace + boiler as a central heating installation.

Worked at a coal mine. The dust can be very flammable.

Yes. Grew up in a house without central heating. Learned to build up and maintain fire in an oven as a kid.