Change the oil and filter and let the engine get up to operating temperature. Replace the oil and filter again if it shows signs of dirt. if possible get one of those magnetic oil drain plugs that will pick up metal particles from the oil.
no, the oil is mixed with the gas before it goes in the carb, so there should never be oil sitting in the crankcase.
That is a two cycle engine and should not have a crankcase oil capacity! It should be oil injected with a reservoir jug under the hood, with should have a level line on it.
Vacuum should always be present in crankcase, it is provided by the PCV (positive crankcase ventilation system) pressure is what you don't want to see.
If there is any residue on the spark plug, it will not produce a sufficient spark for the engine ignition.
No, but your crankcase should be vented anyway. If your getting coolant in the crankcase it is getting in from a bad head gasket or cracked head or bad intake manifold gaskets. If you don't fix it soon your engine will be toast.
No, leave the engine off to check the oil. When you start the engine it sucks all the oil out of the crankcase, so none will appear on the dipstick.
None -unless the engine suffers from "blow-by" caused by excessive engine wear or non-functioning crankcase ventilation system
The purpose of the PCV valve is to regulate the flow of crankcase fumes into the intake manifold where they can be burned. Prior to 1963, cars had no PCV and used road draft tubes that just left the hydrocarbon emissions from the crankcase out into the open air. The PCV valve also has a secondary role as a check valve, to prevent flow back into the crankcase. This prevents potential ignition of the crankcase fumes, should the engine backfire. The PCV system is also crucial for to proper engine sealing. The system alleviates crankcase pressure, which can push out on seals and gaskets, contributing to oil leaks.
Yes, but you risk damaging the engine if there is any significant amount there. The oil should be changed immediately and the problem rectified.
If you do not use oil in the engine it will destroy itself due to lack of lubrication. If it is a 2 cycle you mix 2 cycle oil with the gasoline to lubricate the engine. If it is a 4 cycle then you put the oil in the crankcase to lubricate the engine.
That is a sign that oil has escaped the crankcase and is now mixed with the antifreeze, you should check your engine for a blown head gasket.
A leak in a hose or the radiator itself. This should be obvious. Possibly a head gasket. If it is going out the exhaust, there should be white smoke, if it is going into the crankcase, the oil will look like chocolate milk.