Please can someone explain post ARR crafting to me?

I've been trying to level my crafting classes as I go and i've just reached the end of Heavensward MSQ and am now focussing on bringing up my crafting classes to level 60 and i'm completely lost about all the new shit being introduced.

Im at my level 60 GSM quest and i'm told I need the master goldsmith 3 tome, but i can't find an answer for why or if I should care about these tomes for anything beyond this one mission now that i'm planning to just go to a later expansion. I'm seeing 7 sets of tomes, plus demimateria tomes, and I have no idea which of these, if any, I should be going for.

Google is failing me, so can someone please help me out here? Of all the systems and recipes etc, what should I actually be doing to level through and what can I ignore?

Is there a simple way to get what I need without weeks of grinding?

Can I safely just grind for the level 3 tomes so I can do the quests and then move on?
If I do this, is there any reason to actually get the other tomes?