That about sums it up. Try to limit the damage you do to something you can afford to pay for if they do decide to sue you. If somebody seems like a jerk or doesn't appear to understand what you are going to do to their house, walk away.
I make them read and sign this:http://www.beesbythesea.com/Bees_by_the_Sea_Apiary/Hive_Removal_files/Cut-out%20Removal%20Agreement.pdf
I doubt it would be much protection in court, but it does help to avoid misunderstandings, which are what will most likely put you in court in the first place.