You need to go out and buy special coverage for your home-based business. Every now and then you'll hear about something like a house where oil is pouring out of the walls for no good reason and the Virgin Mary appears in the oil. If that happens to you, and you make a claim for the damage done to your walls, you're covered. Cars and trains fall under coverage for damage from vehicles hitting your house, while airplane damage is paid for by coverage for objects falling out of the sky. A terrorist act such as this would almost certainly not fall under the exclusion for war.
Nuclear accidents are a standard exclusion.
You'd have to go to the power company that owned the nuclear plant and get it to pay up. If you build or buy a house on a cliff, hopefully you are aware of the risks involved. Your standard homeowner's policy won't pay if your house slides down because of a landslide or any other reason. Your best bet is to go check with your agent about getting coverage from surplus-lines insurers. This is a problem for homeowners in the Coal Belt states, including Illinois, Ohio, Pennsylvania, and West Virginia.