Well, first off, check the oil pan bolts. They have a tendency to loosen up just like valve cover bolts. they are only something like 8-12 ft/lbs so just give them a snugging. You have to define the source before you can guess how critical it is. Generally, you should be ok as long as you keep the oil reasonably full, but by principal, I hate people who drive cars around that piss oil. Bad for the environment and makes motorcyclists crash. Yeah, I know not many motorcyclists in MN in the winter, but you get the point.
Yes, the fan clutch is a replace item. The good news is that it is easy. In MN in the winter, you may not need it. Watch the temp gauge.
B