I wonder why, with divine metal, angels, vaults, and other new fun things being introduced, why do we only get to experience them in adventure mode without a lot of effort? My proposal is to introduce an event, weighed the same as a dragon or hydra attack, based on population and wealth, that involves a single merchant and donkey appearing on the map. He'd slowly make his way to your trade depot, bringing what looks to be a small amount of goods. Then, upon opening the trade menu, you see it- this unsuspecting merchant is most likely sent by Armok himself. Masterwork and superior steel items, rare gems by the bucketfull, aluminum trade goods, bones from rare animals, all the things you'd toil away forever carried in on one donkey. But, when you try to leave that screen, he says "Wait! There's more." Or something similar, and if you agree to continue trading, a menu full of bars of divine metals and basic items made of them will be revealed. Not only does this merchant carry prized and hard earned items, but he comes with regularily unobtainable metals for you, in small amounts, of course. Since there are so many types of divine metal per world, you most likely couldn't make large objects out of them without exploits or waiting for the rare chance this merchant will show up again.
So what do you think? I've always thought that someone should be carrying stolen metals from the vaults, ever since I saw once in legends mode a kobold who snuck into a vault and stole a sword. The prices would be high, but most likely worthit, to get masterwork goods and average quality divine metal goods.