A nit pick on #1 & 6: There historically have been a very few oil seeps where small amounts of oil have collected on the surface. This is how the ancients got their pitch to caulk and seal boats. I believe the LaBrea tar pits in LA are an example of an oil seap with which some of the students may be familiar. We are talking about a truly tiny amount of oil overall.

The fact that oil is found beneath the earth's surface doesn't preclude it also being found on top occasionally. I believe that many of the older fields were found this way.