Asbestos, cement shingles usually have 1% asbestos in it. The shingles are harmless until you start breaking them (for whatever reason). When you want to paint them, if they're attached to the house using ferring strips, then they should be secure enough to use a power washer to remove any loose paint. If they're attached right to some type of 'soft undersiding' (like gypsm board as they were on my house), you'll have a manual job of wire-brushing off the flakes. Wear the properly rated masks and filter for asbestos fibers. (I know Home Depot has them in the hardware department for $20 or less.) I suggest you go to a Paint Retailer (see Yellow Pages) for a quality paint. Be prepared to pay some $$$ because it is a special paint. Do read the can BEFORE you do any prep work because there are good tips on them already. DON'T skimp on the paint!!! Otherwise, you'll be painting in 5 years. A few extra $$$ are worth it for paint that will last 12+ years. (YOu may have to prime so read the can.)
Since the home is being sold as-is, you ought to request a Seller's Disclosure Statement. If you're implying that the Statement is a foregone conclusion, and it's as it, then be sure to tell this to the Home Inspector. Make sure he/she is ASHI-Approved. Find out how long they've been practicing, what their expert background 'in the trades' is, and hire someone who is going to give you a report ON THE SPOT. You don't want to have to wait 3, 4, or more days for one. By then, the inspector may forget things, and if you have any questions, it's best to ask him/her while they're at the house. Make sure you are allotted the time to review the report before he leaves. I'm not an inspector but if you live in the SE PA area, I can recommend one. Try and find someone whose background is at least in the trades or in some degree like civil engineering, or somethin'. Stay away from inspectors that use to be teachers or programmers or things like that. FWIW, my inspector had a degree in civil engineering and his partner use to be a home builder. They have combined experience of 35+ years.