It will pas vapour yes
- but as this goes back into the inlet it is condensing and this is where the oil build up is created as it dries back in the inlet.Once it begins to heat agin during running of the engine it turns back into oil and is sucked through the system
I agree with you a lot of oil is bad
- as you say. However would this not be a simple way of measuring how much crap is going into his system and where it is coming from (exhaust wise)This could be a mixture of rings on the way
(smoke out of the exhaust direct from blow by) and in the turbo from it brathing heavily.i think either way the way forward is t ofit the catch can to diagnose where the oil is coming to the system
(through the inlet and burnt, or as blow by)- then sdend the turb off to a rebuilder to have it checked (turbo technics charge £39.00 picked up, stripped diagnosed and sent back to you). if all is well on the tubby - then yes - fooked ringlands.Just the way i would do it thats all
(as I have had to as the car simmo sold me is a dog!!!!!! turbo has had to have a £600 rebuild (only rthe casing was serviceable) and the ringalnds are shredded!so a car that cost me
£2200 has actually cost me over £4500!!! - so he was right it is a £4k car 
cheers
Mike
