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.
The WoW token is very simple: You pay Blizzard $20 for a token, and then you can sell the token on the in-game auction house. A player with gold can buy a token and redeem it for a month of WoW subscription time or for $15 of Battle.net balance, which is like a gift card credit that can be redeemed in WoW or other Blizzard games such as Hearthstone and Overwatch. You get their gold; they get your cash, or at least most of it.
There are various upsides to this imbalance. Max level players are able to complete lower level content with ease, allowing them to swiftly complete missed quests and achievements in earlier zones, and can travel through zones without being constantly attacked, since mobs will only attack players several levels higher than them if walked directly into. Max level also makes it possible to solo earlier group content such as dungeons and even raids, making farming loot such as mounts far easier, and for those interested in a challenge opening up a new subtype of play at slightly higher levels.
Instead, go to Timeless Isle and take the portal to Gorgrond. From there, fly to your respective faction starting zone(Frostfire Ridge or SMV), go to your garrison, and do the quests to unlock your garrison(A short quest chain beginning down near the water where you'd otherwise start after the Dark Portal scenario). For now DO NOT collect any more treasures than absolutely needed to buy 1 or 2 experience potions! Treasures continue to be worth superior exp/h all the way to level 107!!! You don't want to begin collecting them until lvl 100 or later.
Vol’Dun is the hardest and most tedious of the Horde Zones in Battle for Azeroth. It’s also probably the one that makes the most sense. Each sections of quests leads directly to the one you should do next. For all of these reasons it’s going to be best to get this one done early. Thanks to any legendary items you might have collected in Legion, you’ll be strongest in the leveling process before 115 and weaker after — because that’s when the legendary effects stop working.
Edit 20 It’s been a week since this post and a lot of people are still reaching out to me with questions which is fine. I have had a few different people reach out to me to help make YouTube videos based off this guide and more info in BFA which I’m more than willing to do. Whoever gets the videos up first I will link them here for you guys to enjoy.