Two minor balancing issues:
With the 3 food per population the Malakum Aduar is not a very good improvement. I suggest that it provides +1 food with Currency and +1 commerce with Taxation. This would make it a +2 food, +1 hammer, +4 commerce improvement in total. I feel this is balanced enough considering how long it takes to grow an Aduar and how easy it is to destroy.
The Khazad worldspell "Mother Lode" has been severely nerfed when you exchanged mines for quarries. Simply make the spell grant 25 gold for every mine and quarry and it's back to strength again.
With the 3 food per population the Malakum Aduar is not a very good improvement. I suggest that it provides +1 food with Currency and +1 commerce with Taxation. This would make it a +2 food, +1 hammer, +4 commerce improvement in total. I feel this is balanced enough considering how long it takes to grow an Aduar and how easy it is to destroy.
The Khazad worldspell "Mother Lode" has been severely nerfed when you exchanged mines for quarries. Simply make the spell grant 25 gold for every mine and quarry and it's back to strength again.