Oil coming from the d/valve is a classic sign the turbo's fookaddd.

Take the boost pipe off the turbo m8 and see if theres any excess play in the turbo, i think there might be, this means the seals in the turbo are fooked meaning replacement time,

this would also explain the white smoke your seeing...

as for your starting probs, im not sure most probally your i.c.v.

Regards - Adi