[rprasad]

Fun fact: in California and New York, you are legally required to inform the new owner that the fan was not installed by a licensed electrician if the installation involved any more electrical work than simply plugging it into an outlet.

You would not be entirely responsible for killing the future owner...but yes, under the doctrine of negligence, you would be at least partially responsible for killing the future owner. In fact, this is one of the first things you learn in your first year of law school.

The unlicensed kid: That depends on how he cuts off his foot. Was he distracted? Was your wife distracting him at the time sunbathing nude next to the pool? Was he using your mower? Was your mower broken?

Unlicensed painter: Also depends on the specific facts. Was it his ladder? Why did he fall off the ladder? What did he fall onto? Would such a fall normally have killed a person? What special facts in this situation resulted in the painter's death?

Protection from damage: You're spot on. In fact, in Ohio, you're required to hire only licensed and bonded (i.e., insured) contractors for renovations or construction work. Moreover, contractors are required to provide proof of license and bond before they begin work or try to collect payment.