Both my cars hate me! + Q

So being as it was nice weather again today, i finaly got round to replacing the knackerd rear shocks on my beetle.
Hopefully it'll stop the exhaust scrapping on the floor every time i give it some beans.

Anyway did both sides with no problems in about 45mins, however when i was doing up the last wheel nut, all of a sudden, twang, the threads gone all loose.

Yes ancient drums = kippered thread.

No worries i thought i'll pop down to GSF to get a new drum in my 5 Turbo.

So walk to lock up down the were it's kept start it up, warm it up etc before driving off.

curse word traffic everywhere, so when i do get the chance to put my foot down on a dual carriageway i do.
Going past something, boost comes on and i hear what sounds like gravel hitting the inner arch.

It's not until i use the boost again that i notice it is now doing the same gravely noise, but only in 3rd, 4th and 5th.
It is also hesitant and very lumpy at idle, and in first it wants to Kangaroo all the time.
Drove home without using the turbo.

When i open the bonnet there is a loud hissing, like air escaping from somewhere, but can't quite fathom out where it's coming from.

So any ideas? Could it be my turbo bearing going, or something more horrific?

Bloody French cars