Let me try to recap all the factors to take in consideration for crafting. Maybe it could help you understand a little bit more. If I'm off the track or if there is any errors bellow, please let me know and I will correct it.
The account skill trees:
You can leveled 2 trees at the time : Combat, exploration (harvesting) and crafting.
The bonus gains thru the account skill trees are for all the characters.
Skills in those trees are a must for gathering and crafting. But, because you can only train 2 at the time, you need to sacrifice a portion of combat vs crafting vs gathering. That's why some people will get 2 accounts to maximize the use of the points. Considering the fact that the points gained for the skill trees are time based (meaning you gain points even when you are offline), you can level 2 accounts at the same time.
First account leveling the skills tree of Combat and Gathering
Second account leveling crafting and something else
The vessels / race :
The vessels is something you can equip on a character base on the race. It represent the "body" of you soul. When you level up and gain point for your base stats (intelligence, strength etc.), it's link to the vessels. So, if you change the vessels on a existing character, you need to level up the new vessels from 1 to the max level.
Some vessels have better stats for crafting, based on the race bonus. So for crafting, you could chose a race that fit better with what job you want to do has a crafter.
For gathering : bases stats impact the gathering : strength for mining , dexterity for skinning etc. So depending on how you spend your points on the vessels, it could impact your gathering skills. I'm not sure if this impact the crafting.
Discipline add skills, stats and passives to your character. Depending of the rarity of the discipline crafted/bought, it gives you certains bonus.
Disciplines are equipped on your character. When you want to change a disciplines, you cannot keep the old one. You need to destroy it to equip the new one.
Some disciplines are specialized for crafter, gatherer or for combat.
Because you can't swap disciplines like you switch gear (equipped discipline need to be destroyed before changing it), crafters will get disciplines that give them bonus to crafting. So this is limiting you in mixing crafting, gathering and combat discipline.
Gear can give you bonus to crafting, by increasing success chances, experimentation success etc.
Dedicated crafters will focus on getting gear giving them the most bonus to crafting. Considering how time consuming it will be to get really good gear, getting combat gear and crafting gear of really good quality will be time consuming. This situation will be true for the ones with 2 accounts.
Dedicated crafters for guilds will focus on maxing all the possibles stats for their profession, based on the previous points. The impact of this is this will minimize the possibles stats for combats and gathering
Dedicated crafters in guilds will have group of dedicated gatherers to get high end mats.
At the end, it all depends how and what you want to play.
You want to be a jack of all trade , combat / crafting / gathering : you will be able to enjoy the game, but you won't excel in one specific category. If you don't care about min/max or being a dedicated crafter/gatherer for a guild, it's perfect.
It's important to remember that the game will be highly focus on grouping and guilds, based on the dependency of the triangle Crafter / Gatherer / Combat.
If your main goal is crafting high end stuff, here what I suggest :
Choose 1 profession: Blacksmith, jewel crafting, leatherworking etc.
Focus you accounts skills around that profession.
Based on the profession : choose a race that give you a bonus to it. That means you will be limited on the classes your can play.
Find a guild where you will have gatherer and combat to help you. Support from other players is probably the main factor of succes for crafter. On the other side, you will have to provide crafting gear to those players. It's a loop of collaboration.
I hope this can help you and other players in understanding what is impacting crafting in the game.