Hi guys,
Update on the idling problem I've been having with the selespeed. Got some free time today, so removed the throttle body to inspect it better.
All inner workings appear to be fine and no sign of any damage, no teeth missing off any of the cogs etc. The rear of the throttle was quite grubby as you can't get to it from the front without removing it, also the area around the edges of the butterfly was a bit grubby looking so I gave the whole lot a nice clean with some carb cleaner and a rag. Also removed some crud from inside the inlet manifold behind the throttle and gave it a clean too.
Finally reset the throttle by disconnecting the battery and touching the connections together to clear the memory. Then doing the 90sec reset on the throttle pedal.
Left idling for a while and initially seemed ok, but once nicely warm started playing up again with the revs going from 1200 to 2500 and bouncing between the two. Then the injector light came on

so connected it up to AlfaDiag and read the fault code as MAF sensor out of range.
Disconnected the MAF, reset the throttle again and went for a spin. the high revs are now gone, idle stays steady at about 950RPM (thats not to say it's fun to drive, very jerky and nearly stalling at times) but this tells me it may have been the MAF all along. Strangely though, there's no obvious lack of power, and no problems getting to high rev's.
In summary, anyone having this problem with the electronic throttle, try changing the MAF early on, it could be a hidden fault. I suspect that cleaning the throttle has just made it more obvious (why I don't know), or else I somehow knackered it by removing it. I'll let you know when I get a new one if it's fully cured.