don't remove piping...remove the wastegate spring to keep from boosting. there was so much oil underneath the hood that it probably got in that way. it is quite possible the seals are gone. the one way to tell is pull the charge pipe off and see if there is oil in there. if there is then the seals are gone. blowing oil through the intake will kill power, but your power issue was because your wastegate was blowing directly back into the intake of the turbo and that is more likely what your seeing in the intake of the turbo.

also, considering where you got your turbo and everything you learned about your original transaction/purchase of your parts, it's possible that turbo isn't new.