All leaks need to be sorted.
It's very common to setup RS Turbo's up rich by people who really should no better. The fuel pressure will prpbably be too high. Oil in the hoses is due normally to 2 things. If its very rich, you'll get petrol in the oil, and ot starts seeping past all the seals. The std breather system breaths back into the metering head, so as an engine gets older, more oil appears in the inlet. Sort this by getting a breather that breathers to atmosphere.
Thirdly, but v unlikely, is that oil is seeping past the turbo seal into the compressor housing.
Rick.