Yesterday I checked the oil and levels as I usual do and I noticed the coolant level has dropped to the mimium level (was just under the maxium level a few weeks ago). Should I be overly worried? How much coolant should it loss (if any at all) Oil is all ok.

Second thing I noticed is when cold and I push the clutch down the clutch makes a buzzing noise this will stay until I've driven a few miles, again should I be worried?

So far I've had 48k miles of trouble free motoring

When you say buzzing noise, Do you mean a change in the engine sound?

not the engine changing it's sound but a buzzing almost as if it was the clutch bearings, or atleast it's what it sounded like on a mates car when his bearing where gone.

re coolant , make a note of where the level is with the engine cold , and then keep a close eye on it over the next week , any more level drops could mean a leak , but the pink antifreeze is difficult to spot leaking until there is a large crusty deposit , make sure theres no chaffage on the PD160 intake pipe