known of a few throttle body's to go, but that prob wouldn't explain the maf thing,
my mate used to be a vauxhall master tech, and i know they had issue's with ecu's
but i'm not sure if it was anything like the prob you've said
i'd imagine if it was they'd know about it and would have done it under warranty
couldn't poss be the chain stretched?
if the maf was disconnected and it as running on base settings it might not notice the cam sensor is out of alignment? just a thought knowing what the chains are like on them