Sitting at idle does not put any load in to the oil and the oil takes an age to heat-up, the oil when cold doesn\'t provide the correct design flow (oil thick - viscosity incorrect), and leads to accelerated wear. This also is the same for the injected oil. The coolant system takes longer to heat also, this means the combustion chamber walls remain colder for longer, so you get fuel condensation, which washes the injected oil from the places it need to be - again accelerated wear.
Depressing the clutch, disengages the gearbox from the engine, so the starter has less work to do, again when oil in the gearbox is cold it thickens up. The clutch is a spring plate and requires the just about same loads when running or not, cannot see how wearing the cylinder could occur, you more likely to have wear from not having clean oil in the clutch hydraulic system?
Best advise with any engine is start and drive. Keep engine loads low (low boost or no boost) until heated and don\'t revs the nuts of the engine, until oil temperature is heated through, to ensure the injected oil rates are correct and the bearings are supported correctly. The more fuel injected - the more oil that is washed away.
After writing this it sounds like a good idea to add 2 stroke oil to the fuel tank- even if it just for cold start/warm up protection!