Everything you say tells me that you don't make and haven't tried to make Sky Golems for goldmaking. Time Consuming craft? It takes me 20 minutes per day to log in on 5 alts and produce jards. I might farm SoH, but that's a great Gold vs time spent farm. 20 minutes equals 10 SoH, 6-8 GI Lockboxes, and a ton of BoEs which I mostly vendor. So all in all 20 minutes of farming is about 10k gold. As someone that doesn't have that much time to play but still wants to pay his sub with gold Sky Golems are the only way to go. I'm in plenty of other markets, but SGs sell within 3 days for the best profit.
At the end of Legion, the titan Sargeras was imprisoned, but not before he plunged his sword into the planet Azeroth. This not only devastated a massive area (much of the desert zone of Silithus is now cracked and scorched), but badly wounded the gestating titan inside. While the heroes managed to ablate the worst of the damage (at the cost of the majority of their artifact weapons' mythic power), the world is still wounded and bleeding a substance called "Azerite," which has great magical potential. The Horde Warchief, Sylvanas Windrunner, attempts to consolidate Horde power on Kalimdor and gain a monopoly on Azerite (which is primarily found at the southern end of the continent). Her campaign to do so, the War of Thorns, formed a pre-launch event for the expansion and ends with the major Night Elf holdings on the continent seized or (in the case of their capital city of Darnassus) annihilated. The Alliance makes a retaliatory strike against her home base, the Undercity, which was formerly the human capital of Lordaeron. This succeeds in driving the Horde out, but before leaving Sylvanas saturates the area with disease and toxins that render it uninhabitable. With this tit-for-tat military exchange, the Horde has almost complete control over Kalimdor, while the Alliance has near-total dominion over the Eastern Kingdoms. With further conflict inevitable, Battle for Azeroth takes the two factions to the continents of Kul Tiras and Zandalar to recruit new allies in order to turn the tides of war.
"Essentially the Scrap-o-Matic 1000 (and Shred-Master Mk1) works like the Obliterum Forge in Legion however one major difference from Legion is that you can use it to break down any gear obtained that is from the Battle for Azeroth expansion, including dungeon/raid drops, quest rewards, world drops and crafted gear. Apart from a chance at getting Expulsion you will also get ore, gems, leather, occasional enchanting mats (from scrapping cloth gear) and other crafting mats. The best way to obtain Expulsion seems to be from breaking down rare/epic gear you obtain from dungeons and raids, killing rare elites and doing world quests, it also drops rarely from BFA uncommon quality items."
I don't think that made professions all that useful. And it was a huge burden to the fun of getting new gear. I like that if I get a new piece of gear in a raid I can generally equip it right away. Couldn't do that when half the gear you get need enchants/gems/whatever. Why not just bring back re-forging then? Though I did like upgrading gear when that was a thing.
-PvP- Completely broken for some classes and I mean broken going from both sides of the spectrum, from classes destroying everyone, to classes that can't even kill another player. It's fairly common for a weak class to lose to a powerful class even if the weak class outgears them by 50+ ilvls. That's how broken PvP is and Blizzard doesn't seem to know what to do to fix it other than do blanket damage nerfs/buffs as those are the only changes we've seen.
But every new character made that wants to craft old expansion stuff will have to level using expansion specific materials. Stocking up on profession materials that are already high in demand can be a great idea. This will primarily be materials used to craft the various mounts. Ghost Iron, Trillium, Living Steel, Pyrium etc. are all great candidates to stock up on.
Welp, not clear on what to do or what to invest in, but (to me) the Key point professions will be alchemy, inscription and blacksmithing, Alchemy raiders will need flasks and pots, so steady income. Inscription for cosmetic glyphs and trinkets the first two tiers of expansion. Then there is blacksmithing that can make ilvl 300 weapons (and armor) that are lvl 110, pretty much like WoD weapons, so they may sell very well through all expansion.
In a few months only mats will be worth anything. At this point we have people with tens of millions of gold and people with just a few thousands. A flask takes tons of mats to make, and they will sell for well over 10k gold each, so the casual players won't afford them. When people realize that the rich guys will always take buying from the AH over farming their own mats, the prices will go even higher, then casuals will notice how expensive flasks are, and they will pick up alchemy and make more flasks, driving the prices down again.