Greetings, all!
I have barely played Dwarf Fortress to its complexity, but have heard and read more about it. Since the Dev Brothers™ want to make this a full-fledged fantasy world simulator, I have these suggestions. (I don't recall reading about these on the planned features page, and searching the forum didn't provide results helpful enough to me regarding the existence of these. Apologies in advance if this stuff has been implemented, suggested, or is scheduled for inclusion.)
In Adventure Mode (or/and in perhaps another, new mode), I would like the ability to manage cities and nations. The game already has nobility and governments. I am well aware that Dwarf (Fortress) Mode exists, but being able to be a part-time noble, part-time adventurer appeals to me.
Similarly, I would like to be able to buy/rent and operate businesses. This may mean making a Wizard's Tower/Magic Guild to supply an area's magic needs; a livery stable and animal hospital for the animal needs; a criminal underworld for 'protection rackets,' poisons, lockpicks, and other goods and services of questionable repute; churches/temples/religious sites for healing and religious/spiritual needs; and general stores for storing general things - all at the same time if I had the resources and desire. If I merely wanted a small-scale business, I could, but if I wanted a chain business (a restaurant in many locations in one city or a guild with a station in many cities) I also could.
Since I can't be everywhere at once, I would need staff. This includes managers to oversee the operations of each location and report to me the information, such as what each branch needs, where it has a surplus or things are otherwise going well, who else to consider hiring/firing/killing/demoting/promoting, and what other goods or/and services to stock/be involved in. In terms of governing positions, I'd like to know generally the same things: What needs short-term attention, what needs longer-term attention, and what things are going well, how, and why. I would also like the ability to fully outsource this organization or set of organizations to managers/NPCs while reaping the profits if I have the resources and willingness. (This game is still meant to be engaging to players.)
I mention Adventure Mode since I like the notion of using the same character as part of adventuring and business/city/nation management. Perhaps invest in a business, work it part-time, and use the profits to outfit my character with vanity housing. Sure, I could theoretically sleep on the floor in my blacksmith's broom closet, but having something more elaborate seems a fitting way to spend my capitalistic gains.
And, this being Dwarf Fortress, I expect there to be challenges in owning and operating a business. Perhaps cargo was attacked by raiders and perhaps some key staff members are being held hostage. Perhaps due to war demand for weapons has drastically increased, which would greatly help my smithing empire but also made the price of ore drastically increase due to trade route problems. Perhaps some megabeast has been created, summoned, awakened, or driven mad by Wizards in a guild I own and needs handling. Regardless, adventurers have something to do that's adventure-like involving their businesses. The bigger the span of the business (or government), the more likely the need for adventuring intervention from the player character or/and other adventurers. Being able to have a private military company (or be the government with a regional or national army) also seems appropriate.
(As an aside which I initially assumed, goods and services and employees would be of varying qualities. You could, for example, specialize in selling high-end jewelry or all jewelry regardless of quality. Your managers could be super competent but demand high compensation or be inexperienced and possibly less reliable but cheaper. That sort of thing.)
I understand that fully implementing this would likely take a significant amount of development time and resources. It need not be included right away, but its inclusion would be a reason for me to learn more about Dwarf Fortress and play it. If this system is already implemented, then the Dev Brothers agreed. If it's officially planned, that's still good. If fans want to mod it in (or already have and provide a handy link), that's also spiffy. The main point is to get this system in the game enjoyably.
Thankee!