Concerning the oil vapor gasses and vacuums, it is generally a bad idea to disconnect them or purify them at all.
I was going to do the same thing, when my father, who is in fact an engine engineer said that these gases are going back in the motor for several reasons, the most important of which is controlling the acidity of the engine oil and fuel mixture, and relates to engine wear and reliability. So it's not just for saving the environment. (which is even more important i think, but that's another story:)
The lodgement of oil on the inner surface of the Intake manifold can be easily removed if you spray some special additive for cleaning TB's and IM's ..you have to apply it on working engine and have somebody spray in the TB while you pump the gas a little. It does a great job, and all the oil is pushed trough the exhaust
