Insurance is one of those necessary evils: Insurance companies make money when people don't claim or when they can get out of paying a claim. So, they will do everything they can to find a way of not paying.
My dad always used to give me this guideline about insurance which I still follow. If you can afford the loss then don't insure. If you can't afford the loss then you need to insure. Of course there are also legal issues requiring you to insure for liability on auto and when there is a lien holder.
Other than that, all you can do is read as much of the policy information as you can and discuss certain situations with the insurance agent to see if they are covered. I think they are generally honest.