If you're worried about asbestos, check out here:
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Can you coat over it? Many times, as you might see on the EPA site, the best way to deal with asbestos is to leave it in place if it's not something that'll be disturbed. Maybe you could carefully coat over it:
I had some luck making a stippled ceiling in a small area with some drywall mud mixed with white ceiling paint. Apply the mud to the ceiling in a moderate coat (maybe 1/8" thick or so). Take a stipple brush (or in one case I used a push-broom head) and press the bristles into the mud and pull back out. It'll look rather sharp and spikey, but you can leave it and knock it down a little later - once the mud is somewhat dry, you can take a wide putty knife or scraper and knock off as much or as little of the spikes as you like, leaving behind a finished texture. The wetter it is when you scrape it the more "leather-like" and flat it'll be after scraping.