Hi and

along to

I would find somebody reputable yourself to change the vvt and chain. It's not that difficult to do but if done incorrectly, can be catastrophic!
I found out the hard way.
The turbo may well fail at some point, but not always. It will become apparent if it does. There are a couple of things that can be done to extend the life of them if it's not already on it's way out.
Firstly, buy a banjo bolt. Cost less than a fiver.
Also the isle revs can be raised to reduce oil pressure at the turbo. This does require more money to do.
But don't let any of this put you off. They are great cars and fantastic value for money imho.