As Horde, the path to get me to Searing Gorge the first time was to fly in from Undercity to Stonard in Swamp of Sorrows, run West through Deadwind Pass, West to Duskwood, then to NE to Redridge, N to Burning Steppes, cut through Blackrock Mountain, and pick up the quest, “Caught!” in Searing Gorge.
A much much easier route is to fly in to Kargath, Badlands run South to 52, 61, and cut over to West into Searing Gorge through the mountain path
Also, once in Badlands and going to to Searing Gourge, it wanted me to take the flight path from Kargath back to Swamp of Sorrows and run all the way back up to the quest turn-in. It doesn’t appear the guide “knows” about the cut-through in the mountains from Searing Gorge to Badlands.