"Essentially the Scrap-o-Matic 1000 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 Expulsom you will also get ore, gems, leather, occasional enchanting mats (from scrapping cloth gear) and other crafting mats. The best way to obtain Expulsom 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."
If you're a new player and buying gold (for some startup money) isn't an option, there's nothing wrong with gathering (especially if you're getting BfA...it'll be good gold initially if you farm BfA mats and sell high). You can make pretty good money just flipping stuff...and because Legion items are super risky now, it's a good time to get spirits of harmony (just buy what you can and sell it in in bigger stacks at higher costs or turn it into ore/bars or lotus to sell when that is profitable). I'd avoid putting all of your gold there though. Sometimes a bot or just someone returning to the game will dump 10+ stacks of 200 spirits cheap and tanks the markets for a bit. Flipping (if you get good at it) will make you more gold in than long run than farming but if you don't have much gold either is a step forward from here. They key to making gold is having the flexibility to lock up most of your gold in items and wait patiently to sell them at a good price but you gotta start small (or cheat like me...when I came back in December I just spent $100 on tokens and haven't spent money on anything other than the Collector's edition since. It's a lot easier to make gold if you already have some.
The hexweave bags are still a safe bet unless the new 32 crafting cost is like 10% of them. The one thing I'm more concerned about is the professions squish. This will make the old world items that we've been selling (TBC Dust still sells by 200 stacks easily) only required for Transmog and not leveling. This was a better option for a lot of professions (especially enchanting). Expecting their near-death with the next expansion. :(
Like I said, engineering is the best when you aren't worried about making gold. The Loot-a-rang is super useful, nitro-boosts are nice when they don't fail, and the glider cape enchant is nice too... you get wormholes to Pandaria, Draenor (make sure you have a glider), Legion, and Argus (as well as a couple old world teleport locations)...Jeeves (and to a lesser extent Reeves) and MOLL-E are also super useful (bank and mail access anywhere, repairs, etc.).
In Kul Tiras, the Alliance's initial attempt to gain the nation's assistance ends disastrously when Katherine Proudmoore, Lord Admiral of Kul Tiras and mother to Archmage Jaina Proudmoore, not only refuses the Alliance's request for aide but also orders Jaina arrested and exiled for her role in the death of her father, Daelin Proudmoore, in the aftermath of the Third War. It quickly becomes apparent that Kul Tiras has become mired in corruption and outside threats, so Anduin and Genn Greymane send Alliance Champions to aid the Kul Tirans and earn their trust. Aiding them in this quest are Flynn Fairwind, a "retired" privateer, and Taelia Fordragon, the idealistic daughter of Bolvar Fordragon, former High Lord of Stormwind and current Lich King of the Undead Scourge. The Alliance is successfully able to earn the trust of Kul Tiras by combating the pirates of the traitorous Ashvane Trading Company in Tirisgrade Sounds, the Naga and corrupted agents of Queen Azshara in Stormsong Valley, and the occult forces of the ancient, ghostly warlord Gorak Tul in Drustvar. After these threats are defeated, Katherine is left despondent at her inability to lead her people, and resolves to help the Alliance find Jaina and reconcile with her. The Alliance eventually track Jaina to the prison island of Fate's End, where Gorak Tul, having survived the events of Drustvar, has kidnapped her and is tormenting her with visions of her past failures. The Alliance champions and Katherine destroy Gorak Tul once and for all and rescue Jaina, who is finally able to let go of the hate, anger and obsession with the past that defined her ever since the destruction of Theramore. The Alliance and Proudmoores then unite to defend the capitol city of Boralus from a massive pirate siege, after which Jaina is named Lord Admiral and pledges Kul Tiras' navy to the Alliance.
But then you have some professions, Inscription, Jewelcrafting, the gathering professions, etc. which don't seem to have any specific extra bonuses for being them. Inscription has been in a bad place for a while and that trend seems to be continuing in BfA, although considering we are not locked to certain glyphs anymore (like having to choose between only one glyph of many for things like Travel Form) I suppose there's a chance we will see some more profitability out of it.
I think that's server dependant. I make a lot of Golems, but the price on my server is high enough that you could buy all the living steel and still make about 20K (almost 200kg on AH). Its just that you proc all the way up the chain. You proc 20% of your trillium, and then 20% of your living steel. SoH and Ghost Iron are such low effort farms, too. 20% of 180 Trillium Bars at 500g is 18k more profit, 20% of 150 Living Steel at 3500g is another 105kg. That's an extra 25k profit per Golem. If they stop selling stockpile them for the next expansion, they always boom with the price of herbs. And a consistent 20% proc rate is the opposite of RNG, its extra free stuff as a benefit to completing an extra quest (not to mention for new alchemists the investment of leveling Vanilla Alchemy). You're looking for some get rich quick scheme, where the real way to build wealth is patience and volume. No market is going to be viable because you want it to be. Only because you make it viable.