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.
Gold in WoW has value based on the time it takes a player to earn it. The various methods of farming gold, such as growing herbs, yield maybe 20,000 gold per hour. That means at a price of 100,000 gold, a token represents about five hours of grinding, or offers a wage of $3 per hour. The idea of gold being worth a certain amount per hour is a useful way of framing this discussion, in fact.
For the 2nd week of BFA, M+, Raids, and Rated PvP are still not open so there isn’t that much that you have to do. Do your Island Expos to level up your Heart of Azeroth, do WQs for rewards, do Warfronts and the 11 weekly quest turn ins, and run your Mythic Dungeons again to try to get the most gear before reset. I personally will be spending a lot of Week 2 farming mats for consumables for M+ and Raids but whatever you choose to do is up to you.
Do quests and complete the story of your first chosen area before returning to your capital to scrap all of the equipment items you acquired. You should be around Level 113 by the time you complete your first area. Before selecting your second zone, head to your faction hub ship to acquire your introductory quests to the mission table and your champions. Complete this introduction and then pick up the quest to establish your first foothold in enemy territory.
The guide should advance to the point where you are in the zone's progression. There are a few steps that can-not autocomplete and they should (hopefully) have comments to the effect of -- you need to manually check this step off. -- For some reason you have to click these steps off 2-3 times to work. (the first time will move the tom-tom arrow, the 2nd time unchecks it and the 3rd click advances the guide).
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.