I'd check that oil leak near your DV, oil escaping from the inlet system is usually a good indicator of a leak. The smell of petrol can be a sign of an exhaust side leak, check the bolts that hold the turbo on to the manifold.
I've kept my eye on the DV for the past 10 months or so and everything is tight, the leak is more like a light brown film around the hose end and never seems to increase in amount.
Everytime I think I've found what it could be something else happens! Just done 80 mile motorway trip and the high pitched squeal sounds now like a dentist drill and the 'whoosh' sound when coming off boost is significantly louder?!

tearing my hair out abit!
I've come to pick my jacks up from my parents house so should be able to have a good look under there in the next week.... In just praying it isn't my turbo

I'm gonna put on my Bosch dv to see if the noise goes as a bit of an indicator!