What is the limit of the face lengthwise regarding the hair follicles in the area of the two receding hairline points, and does the ruling on washing what is beneath them differ between ghusl and wiping, and what is the reason for the disagreement regarding whether they are considered part of the face or the head?

The two (forelock) temples are part of the head according to the majority of scholars, and they are wiped with the head, not with the face. Washing them with the face is commendable according to the Shafi'is, in order to avoid disagreement. The evidence for the majority is that the two temples are included within the boundary of the head.