I don’t think that there are any quests leading to Searing Gorge. There are two entrances. The standard entrance for your first time is from the mid west of Badlands; find this by going south west from the two annoying gnomes in the north west, but avoid the Horde outpost.
The flight path is at Thorium Point, in the north west. You can reach it by going north, then west, from the Badlands entrance, which takes you close to the keyed entrance from Loch Modan – to get the key, you have to kill an elite (level 48/49) close to the outhouse (see below). Watch out for a gang of Undermine poachers that wander the east/west path; if you stay just south of the path, you will be safe from them.
A little way south of the entrance from Bandlands is a couple of tents with Dark Irons and golems. To the east, on higher ground, is a small outhouse, at 66, 62, guarded by one golem. Outhouse – Locked In, then Outhouse – Ledger from Tanaris. For the ledger quest, you can kill the glass web spiders all around this area, then collect two items from clickables. These are in Dustwallow Marsh at the crashed zepellin (54,55), one of the crates under the wreck, and in Swamp of Sorrows on the east coast at the murloc village (91,66). Hand in the results in Gadgetzan. There is a lead in quest to this, which is Outhouse key – The Key to Freedom. The key drops very rarely, at random from Dark Irons; as most of them are much higher level than the Grimsilt quests, you are most likely to find it out of order.
Back at the outhouse, go down into the dig, where you will find a smudge on the ground: Dorius Stonetender – Suntara Stones. This is an escort quest. If the dig site is reasonably clear, he will wander around the edge of the Cauldron among the spiders. Each time he reaches a set of what look like unmineable ores, he will pause for a rest and be ambushed. I think there are three of these, spiders and Dark Iron at various points. Eventually he heads for the locked door to Loch Modan, and will be killed by a Dark Iron sniper; this is part of the plan. You get a final quest to report to Ironforge.
South of the entrance to Thorium Point are two humans, surrounded by Dark Iron remains, very close to a lot of golems and Dark Iron dwarves. His first quests all involve killing here: Kalaran Windblade – Divine Retribution, The Flawless Flame, Forging the Shaft. Levels are from 45 to 48. A couple of patches ago, this appeared as a huge dragonkin floating above a night elf; obviously a bug. Make sure that you also take: JOB OPPORTUNITY: Culling the Competition, from the noticeboard at Thorium Point. You will be killing golems, plus Dark Iron slavers and taskmasters; if you run short, there are plenty more in the Slag Pits.
In Thorium Point, there are several quests to take, start with: Hansel Heavyhands – Curse These Fat Fingers and Hansel Heavyhands – Fiery Menace. as these involve killing in the same area as Kalaran, you should get them at the same time.
Once you have completed these, the next two quests from Kalaran’s sequence are elite: Kalaran Windblade – The Flame’s Casing and Squire Maltrake – Set Them Ablaze! The Twilight’s Hammer are the level 47-49 elites west of Thorium Point. The drop rate of the symbol is 3-5%; shamans seem the most likely to drop it, and are easier to kill than the guards.
The next quest from Hansel involves the Slag Pits. Hansel Heavyhands – Incendosaurs? These are levels 47-49. To reach them, the second entrance to the pits from the east takes you to a large cavern with approximately 12/13 incendosaurs. The easiest way to reach this entrance is by dropping down from the north wall of the Cauldron, but you can work your way through the mines (level 45-48 dwarves) to the easternmost entrance, which is a short walk along a ramp to the one you want.
Inside the Slag Pits is: Dying Archeologist – Rise, Obsidian!, leading to Dying Archeologist – Release Them. This requires more extensive killing of the Twilight’s Hammer in the northwest (29,26).
Near the incendosaurs, through the eastern most entrance to the pits, is Overseer Maltorius (WANTED: Overseer Maltorius, another noticeboard quest). He is a level 50 elite with 16k hit points, guarded by two 48 elites with 5k hit points each.
The final noticeboard quest is for: STOLEN: Smithing Tuyere and Lookout’s Spyglass. Drops are from lookouts, and Dark Iron Steamsmiths – they are found in the same area, and the steamsmiths are rare (39,50); lookouts are all around the towers. Level 48.
Zamael Lunthistle – Prayer to Elune 50 (elite)
Master Smith Burinate – What the Flux? 50 (elite)