Normal, you get a little blow back from the PCV valve system...
your oil resevoir is to full
breather tube from crankcase or valve cover brings blow-by to the air cleaner to reburn. excessive blow by will be heavy with oil in the air.
Extensive water in the oil can damage bearings but, a small amount of condensation is normal in motor oil. It will usually build up on the underside of the oil cap. It can be caused by moisture in the air, or blow by in older motors.
replace the oil pump or the engine could blow
The best way to know if an engine is 2-stroke or 4-stroke, is to look for an oil spout. If the engine has an oil spout where oil has to be poured into, it is a 4-stroke. If the engine has no oil spout and the oil has to be added to the fuel, then it is a 2-stroke.
that's normal.
The engine is getting worn and blow by is getting into the crankcase and forcing oil from the valve cover into the air breather.
No, not on a normal air filter. But if it is an oil filter yes you apply oil to the filter.
use an air compressor hose with a nozzle designed to blow the air on it, or a can of compressed air.
Just as you can blow out a burning match with your breath, explosives are used to "blow out" oil well fires. The fires are so violent ind intense that normal firefighting methods will not work.
maybe if you had an oil tanker