Don't let it sit. The water/antifreeze in the oil will make an acid that attacks the main and rod bearing metal.

The "smoke" was mostly water vapor, plus fuel fumes from the wet cylinder that wasn't firing. The hotter the exhaust got, the more steam.

PCV valve replacement takes 5min, and should have cost about 20bucks in labor plus a 15dollar part.

Unless you have have several overheating events, I doubt the head is cracked. New heads are under $300.

Not responsible for advice not taken...