It's not too late to make DoL/H actual classes
Note: A work in progress.
So the original vision of the game -- as it was explained, anyway -- was that a player could be anything they wanted, even a miner or an alchemist, and still be considered a "class."
For one reason or another, which likely never will be known to the players, the game was rushed out the door seemingly a little early nearly a year ago.
Since then, a lot of focus has been placed on battle mechanics and the class and job systems. Rightfully so, many people come to any game to do battle wit the big baddies.
But still there hasn't been much said about DoL/H and their future involvement with the world of Eorzea. Of course there are things such as Materia and recipe alterations, but what about storylines and a crafter's/gatherer's character having a greater affect on Hydaelyn?
Granted, a DoH/L shouldn't be able to walk into the Dzemael Darkhold and go toe-to-toe, but that doesn't mean they have to be relegated to production line workers either.
Raiders of a Lost Art
While battle classes slay the fiends that lie in wait in Toto-Rak and Dzemael, so too should DoH and DoL have their own raids. Chances to net some SP and rare gear outside of grinding the same recipes over and over.
Gatherers
For gathers, I envision archeological digs and and espionage-style missions. DoL classes could be tasked with entering dungeons tasked with locating malfunctioning magitek that has made the creatures in the area invulnerable. Realizing what was the cause of their new powers, the creatures have hidden the item. It's up to the gatherers to use their talents and communicate to avoid being detected by the area creatures. This could involve all three classes as the item could be hidden anywhere.
Another concept would be that a plan has been developed to stop a Garlean advance by created a sink hole under where they are expected to march. Only problem is the cave where digging was set to being is home to a rare species of fish. While miners weaken rocks and botanists dispatch of roots, fishers have to pull out enough of the fish so scientists can ensure the fish can be bread in captivity till a new home is found
Crafters
Crafters are a bit easier to come up with general concepts for.
One idea is an ancient sailing vessel being discovered, but the only way to get it out is to sail it, and for that to happen. Unfortunately, those that discovered it tried to sail it before they checked the hull. Now it's sinking. They crafters must band together to create some kind of watercraft to get to the sinking ship so that they may patch it enough to get it to dock.
Crafters could even find their way onto a battle field, albeit behind the lines. A grizzly battle is taking place and the crafters have been dispatched by the Grand Companies to aid in anyway they can. At the battle, the crafters must repair equipment, supply rations and potions and other alchemical aids.
To prevent instant win by entering with the items made in advance, the ingredients for special items would be provided upon entering.
The World Needs Supplies
Another way to give a sense of "world involvement" would be to have DoL/H supply places like settlements and hamlets. When eventually hamlet defenses are introduced, the level of supply could have a significant effect on the outcome.
The supplies could be lesser-desired items like low level gear or lesser-used potions and food. This would significantly stimulate the game's economy by moving mob drops and ingredients that would eventually get passed over once the game's population becomes more top heavy.
A Story of their Own
It's obvious by the current main storyline, that a series of quests devised to include DoH/L is boring for battle classes.
That's why battle classes and DoH/L should have different paths within the same story.
Where battle classes fight their way through a story, DoL/H must interact with NPCs unique to that those types of classes to advance in their own side of things. It may not be the pulse-pounding action that battle classes experience, but those with money tend to be those with power and the behind-the-scenes can be just as intriguing as the time spent on battlegrounds.