Yeah, your probably on the right track. Pull off the intercooler and look for oil - there is typically some residue or maybe a little that you can dump, but definitely not a puddle. With that off you can get to the PCV, I'd just replace it. You can pull the DP and see if the turbo is leaking out that way (maybe let it idle for a few minutes first in case it is all burning off during normal driving). You can also pull the plugs and see if there is oil on any or all (any would be more likely an internal problem, all would be external). They are a bit of a PITA to get to but if you take them out you can do a compression test as well.