So most of the responses do seem to be backing up my original points.

Crafting is only useful to make food to raid with, and I agree with that. Which means that botany, fishing, and culinarian are currently the only useful/worthwhile DoL/DoH classes to pursue, which also gets back to the only useful thing to spend gil on, is food, although I reckon you'd be hard pressed to not be earning enough through dungeon grinding to not be able to afford food for raids anyway.

Oh, and Carpentry, if NO ONE else in your FC is a high level carpenter, for housing.