Exhaust Manifold questions..

There is not a direct link between the exhaust ports and the engine oil...I don't think those are related. Water in the oil would be from a crack in the heads or block, or bad head gasket. If an engine is run very short distances without ever being allowed to fully warm up, or if it sits for several seasons, it could get condensation in the oil.

I have never pulled an exhaust manifold, so I am unfamiliar with how much water should/could be present there. I just know they are "wet".