I have some thoughts regarding mining and getting raw materials, as well as potential routes for craftsmanship...
First, it seems to me that there is no difference between the level of mining skill and success. I have read some other posts with ideas on how to change this, from finding more ores or more valuable ores. I disagree. Mining should always be tough work. I think that increasing mining skill could easily be rewarded by awarding more experience points whenever an ore is found, depending on the level of the miner. For example, at level 1, you may get 10 XP from finding an ore, at level 2, 20 XP...at level 5 100 XP, and so on. This would make a miner career more rewarding, and bring it more into line with just wanton slaughter for XP's.
Second, NPC merchants could be set up in each city, a sort of marketplace. These NPC's wouldn't buy or sell ores...they would simply facilitate contracts, perhaps for a fee. For example, a smith could place a "contract" with a merchant in Hydlaa for 30 iron ore, and offer 20 tria per ore. He would pay the merchant 600 tria up front for the order, plus fees. A miner could approach any iron merchant in any city, and click on an icon to see what contracts are available to fill. Naturally, he will choose to fill the highest paying contracts. If he has only 10 ore, he can still select the contract for 30 and get his money. That contract would then show 10/30. The miner would be paid his 200 tria and go back to mining...
When the contract is filled, the player would receive a "tell" that his order is ready, an he simply can go to the nearest iron merchant to pick it up...sort of a Western Union system.
In this way, someone who wanted to concentrate on smithing wouldn't be required to mine his own ore if he was willing to pay a premium, and NPC's need not buy ores from players, the market would provide need and value. The more urgently a player wishes to get his goods, the more he pays, and the faster his order naturally gets filled.
The same can be done with all the ores. You could then have a distinct class of miners and skilled craftsmen.
Also, for skills such as cooking, it could be a prerequisite for making potions, or alchemy. These potions must be stored in special containers that only skilled glassblowers can make, unless the mage wants to learn these skills himself. The quality of the potions could be restricted by the quality of his cooking skill and the container the potion is put into.
The same could be done with magical rings. For example, a mage wishes to make a magical ring. He needs a high quality ring to do it, so he approaches a jeweler to make a contract with that jeweler for a very nice ring. The jeweler agrees to the contract, and in turn contracts a smith for gold ingots. He also needs diamonds, so he places a contract with a diamond merchant, which the miners will fill just as the iron ore example above. In addition, the smith, needing gold ore, may decide to contract some gold ore rather than dig it himself.
That is a whole lot of economic activity from what is essentially one mage wanting a ring, and there is plenty of work for other PC's to do. That one ring may involve 5 or 6 players to create, even if they don't know it.