I think, and this is my theory, and only my theory:
i think the perp drove into the area by ATV or other 4WD vehicle, the night before she was abducted later in the night so that there would be no one still out hunting and no family awake to hear him, parking in the open area, (not the watery one the small one just S of Holly's driveway on this map:
681 Swan Johnson Rd, Darden, TN 38328-4830, northwest of Parsons, TN 38363 - Google Maps
From there he could have walked around to the back of her house, and watched as the family went to bed or he could have stayed there and watched as vehicles pulled out the next day. When people, like her mom and dad walked out the next morning, he could have cleaned up his watch site of any food wrappers or other overt signs he was there, and then watched through binoculars until she walked out. At that point, he could have walked right up the drive, put an arm around her shoulders, a knife at her throat, turned her away from the house, and simply said "Walk with me and you'll be fine." he might have hit her to stun her, or he might have relied on shock value alone, and accidentally nicked her or himself with the knife.
At that point, he could have walked her into the woods, around the back of the house through the woods, taken her through the far side of the property either by woods or in the open, not thinking that anyone would have seen her go, down the drive and to the waiting vehicle, then either gone further South, around the shoreline of the watery area, and then to the road, or simply coasted down the drive and down the road. From that point, I think he took hr to the area several miles away, near where the lunchbox was found, gone through her lunchbox to make sure there was not a cell phone, tossed it, and taken her to the spot he planned. At that point, I do believe he raped her. As to whether he killed her or not, to me, depends solely on the abductors state of mind and resources. If he has a place to hold her where he is sure that she will not be found, she may still be alive. If he didn't, then he isn't going to leave her chained to a tree, and she is likely dead and buried somewhere. It hurts me to type that, but it is the turth as I see it.