Since you linked it, I’m happy to provide some quick and dirty information.
I have… many characters, since I’ve played WoW since Vanilla, with a year or two off here and there. Two of those breaks was Rift (which I loved) and SWTOR which was a lot of fun, but had deeep problems in many areas. Although I came TO WoW from City of Heroes, which I loved, but wasn’t always loving the players back (still looking at only 3 quests and NOT being able to abandon them!).
Crafting is and always has been (IMHO clearly) a sink for anything But consumables. And it looks like you’ve been playing mostly in the original setting, rather than the later expansions. It has been improved, with the future expansions concentrating on far fewer materials (generally 1-2 main per expansion, and 2-3 rare sub elements) - but it’s almost always a NET loss of cash. These days I normally go for a dual gatherer and sell everything, buying what I need off the AH. You too seem to realize that the mats for some crafting is far more expensive than the final products value, but for others, YMMV.
And previously, you needed to be at or near the end of the prior expansion’s crafting to train the next, so yeah, there was a reason. But not for the a while now. So no, if you go to dragonflight you’ll spend a chunk of cash and start learning the new crafting with zero reliance on your old skills.
That isn’t to say that there aren’t advantages to crafting, as you can normally get better gear earlier, IF you have a ton of cash to grind, and want to farm the item upgrade geekups, but leveling is so damn fast that it’s really not worth it. Endgame is similar, in that you can give yourself a solid set of gear without doing dungeons, but each micro-expansion raises the level cap and leaves the gear in the dust. Or if you’re super awesome, there’s also the new ‘specialization/skill’ system to further make uber gear, but by the time you’re there… you could already gear past it with drops, unless you’re near the bleeding edge.
So, honestly, the only crafting I would consider is consumables, and it’s STILL almost always cheaper to buy the finished products off the AH.
Okay, enough whining.
So, since you’re coming into this ‘new’ from a more classic sense to Dragonflight, you’ll pretty quickly get the new dragon/drake mount, which has limited flight mechanics compared to the old stuff, but is reasonably fun. You will level like an out of control BEAST, especially if you have rest, so if you try to complete each zones story (some of which is gated by reputation or other completion) you may well find yourself max level before you finish the second zone. For blacksmithing, there are 2 primary metals, one secondary (rare), and various elemental essences, so you won’t have to go to specific zones for specific materials, which is an advantage.
I’d advise that once you are high enough level to GO to DF, to make sure to check the AH and buy some cheap level 60 gear if you can find some - as in many past expansions, the expected gear to enter the door was based mostly on the end game item level of the prior expansion. If you walk into it with more casual gear, well, it’ll hurt, but that means the drops and quest rewards will seem unspeakably epic.
I’d also, if you haven’t do sone already, consider putting together different build options for some of your avatars, unless you intend to focus on dungeon clearing. Sure, you can solo as holy, or marksman, but it’ll probably be easier (especially if undergeared) in shadow or beastmaster respectively.
Anyway, if you have specific questions, check out my other thread, although it’s mostly people going to DF from the more recent expansions, or @ me. For that matter, if you need a cash infusion, I play (a lot less these days but still) on Wyrmrest Accord and if you play or make characters there, I can give you a few tens of thousands of gold or some assistance if needed. I’m not super L33t but I’m competent, and have friends.