A small amount of oil in the pipe post-turbo is perfectly normal. It comes from the blow-by which comes out of the pipe at the top of the back of the engine, and is fed into the air intake just in front of the turbocharger - so don't worry about that part of it.
At 3,000rpm your turbocharger should be going very strongly. If the actuator isn't allowing the flow onto the turbine it could impair its motion (and that might also change its tone). It still might just be the actuator!
Here's the test: start the car and let it idle. Pop the bonnet, walk around to the left hand side of the engine and look under the round gold-coloured widget that sits on top of the turbo. There is an arm underneath, around 8mm thick or so. It should be moving up and down about 3-5mm almost randomly.
If it's NOT moving, there's your problem. Take a look?