If you level crafting on an Alt you will want to level the MSQ on it as well. Collectables and master books require MSQ and gathering requires the map to be unlocked.

I have 8 characters on Sargatanas and 3 of them are 60+ crafters but the true meta projection is in the retainers. Being able to craft is just good for GC seals to feed the retainers. Of the 3 x 60+ I have, one does not have HW or SB unlocked and she has no master books and no access to gathering nodes. She relies exclusively on the other two. In terms of crafting, all on the main is optimal and blue bar won't get gobbled up by crafting. It will get gobbled up by gathering though and you won't want to try and craft without gathering. The cost will be too high.