The front end of the N1 & N2 rotors (ie the fan & HP compressor) are removing most of the energy from the airstream to drive the windmilling process. Thus there is very little pressure energy back in the turbines - they contribute almost nothing to windmilling.
During shutdown or windmill, VSV's should be fully closed - their normal condition to be ready for the next start.
Since windmill is such a low rpm, there is little heat rejection from the bearings, so the requirement for oil cooling is almost nil. Maybe someone else can quote a case of bearing damage after prolonged windmill, but I've not heard of any.