[G UK]

Very much doubt its the clutch, if the pressure plate was knackered you would have trouble shifting and/or be getting slipping.

Sticky Throttle body is a possibility though, should be easy to diagnose that though. Rev the engine and gently release the throttle a few times and make note of where the engine idles after each. If the throttles sticking the idle point will vary.

Does the engine rev when your rolling with the clutch in but drop back to idle when you stop? If so slightly tighten the throttle idle screw until the revs drop a bit, the ecu should try to compensate after a few seconds. Then give it another test.

This actually happened on my Lotus and the idle screw had somehow come lose, the ecu was managing to keep the revs down when the engine was stood still but when coasting it would sit at the higher revs, mine didnt stall though.