Let me answer as an engine professional with no clue at all what you vehicle/engine is:
* There is nothing good that happens when an engine is idling.
* The statement about cooling a turbocharger might be correct if it does not have a water cooled bearing section.
* Changing out lube oil is required by the service the engine has seen. If you don't want to get a lube oil analysis (~25$us), change it at the recommended intervals.
***Some of this might have minor revisions if the vehicle is described in great detail, but I doubt it.
Matt - An Engine Test Lab Refugee
