"And it is certainly not just a service road. Pakistanis have been alllowed to go to the border and back. Pedestrians have been to walk from the border to the complex and back."

They can go to the border (as they can basically everywhere else along the Punjab border) and back because it is a road purposely built to connect the temple with the Indian border reception centre. 

The fact that you realize they can go "to" the border but cannot actually cross it demonstrates my point: This is not in anyway a secondary road that connects two cities or even two villages. It is just a road recently built to connect a temple to an Indian border reception centre. Unlike wagah, Pakistanis are not allowed to step foot across the border, and Indians cannot use this border to go anywhere else in Pakistan except for the temple complex. They cannot enter even the villages right next to the temple.