Your missile scenario is plausible. It possibly explains the last photos on Krivonischenko's and Zolotaryov's cameras better than any other theory. It's a believable explanation of the burned tree tops and some of the odd injuries to Yuri K, Zina and Dyatlov. I wonder though, if a missile exploded near them and burning fuel was falling on tree tops, why hurry down to the trees? Or at least put on hats, gloves, shoes and coats, then head for the trees. Once the missile exploded and they realized their tent was still standing, why hurry in such panic down the slope?
As for a track vehicle running over those in the snow den, I just don't see it. Who knew precisely where the missile was going to explode? Even if the troops were several miles away from the hikers, the missile could have exploded nearer to the troops, putting their lives in danger. Was the track vehicle traveling in the ravine and continued to do so after killing the hikers? Wouldn't the forest be too thickly wooded for a vehicle to get through and up the slope? How fast could a vehicle be traveling in such heavy snow? Wouldn't the hikers have time to scramble out of the way?