2. Today's price very much depends on futures contracts bought some time ago - if in say, June of last year there was an expectation that oil prices would be high at this time they probably will be, because last June people bought futures contracts, based on that expectation.
3. The price of oil on a week to week basis has little to do with its scarcity as a resource, and everything to do with supply and demand. For the past five years or so the supply of oil - that's the amount that is pumped at the well-head - has remained more or less fixed, but demand from countries like India and China have risen considerably. In the medium to long term this indicates that oil prices will steadily rise.