The ideas in the worldbuilding are interesting, if a bit tropey. I think where this really shines is in the characters and potential plot- so, the part that matters most in storytelling, I'd say. It's definitely an engaging, classical thieving crew- each person with a specialty to bring to the table, a regular Ocean's 8.
I do have a question about the money, though- if it's only valuable because it holds a magical spark, and that spark fades out or is used, what happens to the coin afterward? Do you have to pay to get them refilled? Is it a Stormlight kind of situation where they'll still take it but give you dirty looks?
Back to the plot itself, what's the crew's big score? Their plan, the core part of this story? The characters are interesting, I want to know what exactly they're up to- is it more of a serialized thing, like Lupin III and Zenigata or Sly Cooper and Carmelita Fox? Or is this a standalone, one-time, one-shot, big-time heist?
There's a lot of info in the worldbuilding, but most of it seems to be stuff happening leagues away from the core of this particular story- this is fine, but seems less important since the focus seems to be on Urial. It's like- in the original Mistborn, there were other cities offhandedly mentioned, sure, and we later find out more about the world in Era 2- but it's not quite relevant to the story of Kelsier robbing the Lord Ruler, so there wasn't much of a need to focus on it at the time. I'd definitely say focus on developing Urial and Uriu itself. Keep in mind certain things as to why countries form like they do- capital cities, more often than not, end up that way due to being a central location for trade/have easy access to quicker methods of travel, like rivers and coasts. If a city is big and relatively modern enough, it's going to need a lot of resources pouring in to feed the populace. At least one valuable the city produces (things like mines, lumber, wool, etc) for trade and one staple local food resource (arable farmland, sea life, rice fields, etc) would be a good start to creating a basis for the working culture there- bring it to it's logical conclusion.