The most recent run I did on my hunter, I never set foot in Ghostlands, nor did I need to fully complete Dustwallow Marsh. There are a LOT of quest lines in each of these zones that might not be available unless you progress and complete story-line quests in order. Northern Barrens and Andorhal are especially bad in this regard, but many zones you can easily miss out on a lot of quests if you don't do a vital quest. So make sure you keep an eye on the minimap for quest ! indicators.
I defintely think at 118 you should go and do all four of these parts. These are required to unlock World Quests and probably take about 60-90 minutes to get through. If you do these whilst levelling (especially all in one go at 118) then when you hit max level you're ready to go on WQs. You can go finish the zones quests at your leisure over the next weeks/months or never even finish them if you don't care about questing.
This gold making advice is applicable to most players, except if you are an enchanter, in which case there is a very strong case to turn them into dust and essence for your profession needs. As an advanced tip, you can explore the use of mobile apps that let you post on the auction house at the right time because the price of greens tends to fluctuate rapidly, and could mean a large loss of potential gold income.
Something to keep in mind as well is that this will make enchanting materials more valuable, since it is likely most players will now simply scrap their boe greens instead of getting them disenchanted. Also redundant dungeon/raid gear can be scrapped rather than traded to the (guild) enchanter in the run. Less stuff gets disenchanted, meaning there will be less ecnhanting materials, meaning their value will rise. All the more reason to DE rather than scrap as an ecnhanter.
I'm very, very interested in a guide that takes into the following: 1) Dungeon finder; and 2) Heirloom items. I've never helped with a guide before, but would be open to help in collaborating on the project. With the leveling guides I've used (primarily this one) I, too, find that I level at a rate that throws the pace of the guide way off (not its fault at all, I can't say enough good stuff about the guide) to the point that I get frustrated and just queue up for dungeons.