its always a gamble to put ceramic over existing vinyl. I don't do it in my profession, but that does not mean you cannot. It just scares me.
Now, on asb testing, take a bit of it to a place in your local that does this. DO NOT do any sanding of the vinyl until you have it tested. Asb is an airborne particle and its OK if left alone, but when you stir it up it becomes lethal.