The oil seals in the turbo are designed to work best under high pressure/speed so when the turbo is at low pressure/speed then a bit of oil seeps through into the intake hose (turbo output). The crankcase breather (rocker cover) also vents into the intake system. Naturally, this oil will pool at the low points, such as the intercooler but don't be concerned by it unless your oil consumption is unusally excessive. It's this oil seepage that mixes with the exhaust soot in the EGR valve and can clog up the valve and intake manifold, ultimately restricting boost pressure and killing performance/economy.
I'd recommend taking of your egr and intake manifold and giving then a good clean with carb cleaner or paraffin. No harm in disconnecting all intake hose sections and cleaning them through too. If you can be bothered removing the bumper then you can take the intercooler out and tip out any pooled oil as well. Once everything is cleaned, give the car a good thrash every now and then to make sure any oil is blowing through thus preventing soot/oil clogging.
Obviously, blanking the egr stops the soot but that's been covered in your blank thread