At minimum, maximizing the crafting potential of a crafting skill (meaning you only put points into what's needed to make the highest tier items) is going to eat up 9 skill points. If you want an easier time of finding nodes in the world, you're gonna have to drop an extra 3 skill points. If you want the daily bonus materials, that's another 3 skill points. If you want to get more resources from deconstructing armor, another 3, so on and so forth for the other luxury benefits in the crafting skills.

Granted, if you are a completionist you can get something like 300 total skill points in the game, which will easily let you max out two or three crafting professions without impacting your combat abilities. When levelling, though, it's best to focus on one, maybe two if necessary for you to create your own gear while questing, so you dont use up too many points in something that doesnt improve your combat effectiveness.

Personally, I have 3 characters (one per faction). One focuses mostly on clothing, the second mostly on blacksmithing, and the third on enchanting. The bank is shared between characters so it's easy enough to move around materials and crafted items.

I am trying to make my main character an ultimate crafter and level all 6 professions (with a big stress on the 3 gear crafting professions, as the research there is very time consuming). I use at least 4 other alts exclusively for storing specific items: 1 alt for runes, 1 alt for provisioning mats, 1 alt for items my main will use for research purpose and 1 alt for unique or memorable items like all those monkeys. I log each alt in the end of every playsession to take all the items they collect from the shared bank.

The only problem I ran into is gold. Since I am using all wood/ore/leather and deconstruct all trash gear, I do not have much extra gold from leveling. But it works fine for now: level 20, all professions above level 11 and have some points spent on them. I can dps or heal and have no problems in PvE. I even have 5 spare skill points which are waiting for their time (either specific battle skills or specific rank in some professions.)