All points make sense and to some degree are practiced by most all owners. The oil type is really not an issue as what is specified is an all-synthetic oil. Cool-down is a bit of common sense. It's just that many are not in common with reality and will argue it's not necessary. Makes sense to me that even some seconds at idle, out-of-load, would help cool the coolant for the turbo. High rpm is crazy for any street engine. Real racers race on the track where they are mostly paid to race and expect to destroy their equipment.
Good thoughts all.