Saving money is a good enough reason for me to ignore fearmongering. I have a fair amount of faith in my ability to tell junk science from real science from an agenda, and fear of vinyl flooring is not in the middle category.
I also have asbestos siding on my house, and don't appear to be dead yet.
You're not exposed to airborne asbestos.
The floor will be the same temperature as the room unless it is cooled some how. With a slab floor it will be a little cooler on the outside, but the center of the floor will be room temperature. Even dirt is an insulator.
That depends greatly on the type of heat and equipment used. There are many choices.
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