If the smell is greatly reduced in the recirculation mode, the problem is under the hood. If it does not, it is inside the cabin and the wiring and blower motor and resistor should be inspected. If it is an electrical problem it could cause a fire. I have a 1988 Ford F150 pickup with 5.0L V-8. I've parked on clean driveways and left no oil, while at other times it will leave a big oil spot.
Oil leaks are a relative thing.
By this I mean one needs to balance the severity of the leak against the potential cost for repairs. Your particular leak sounds like the front crankshaft seal or the front edge of the oil pan. One way to pinpoint the leak for sure is to use flourescent tracer dye. Most repair shops in town will have access to this method. Using the dye will help isolate the problem so the cost of necessary repairs can be properly estimated.