-there are 3 "gates" for the city, if you add one more you can make "a war" where the smithshop would have more customers (it wold be something to help on the start), but there would be also atacks at the smithshop so the player could use weapons, and to summon this attack? Quite easy, get the four crystals, put them on the air above your head, the will go to the correct "gate" and when all of them arive on a gate, they will become portals and the attacks will start.
-you can do a weapon that costs much money, but to make it you need one of the cristals; FIRE:you throw it on the water, and with the cooled adelite, use the hamen above the anvil, it will make a sword that attracts more customers.WATER:put it on the water, create any weapon, when you cool it it starts shining and attratcts more customers. FEAR: use it with mitrium to create a "ball" and you throw it on an other smithshop and everyone becomes afraid cause the swords broke and everithing so everione buys other weapons only at yours blacksmith shop. "LIGHT": just sell the cristal on a "black market" to get 20k
-The shields are only made with cristals, and who asks shields need to give a paper, he can't go and ask it like a sword.
HOPE YOU ENJOY THE IDEAS! ;)
GOOD LUCK WITH THE DEVELOPMENT