I discovered this game a few weeks ago, and have rapidly wasted many hour of my life since. But there are a few UI issues that really drive me crazy.
One is the setting [KEY_HOLD_MS:150] in init.txt. Why can't keyboard input in game work like normal keyboard input, where there's a delay before it starts repeating, and then repeats at a more rapid fixed pace. If I increase KEY_HOLD_MS, it makes it easier to avoid undesired repeat keystrokes, but then repeat while holding becomes painfully slow.
Next issue is with focus stealing. Often I send out my diggers and then go do other things. They periodically report back that they discovered new mineral types. It's not so bad if it's something like platinum or opals or whatever, but I get really tired of constant interruptions telling me that they discovered alunite or cinnebar or talc or whatever. It never notifies me about stuff like obsidian, marble, granite, basalt, some of which I care about, so why does it have to steal focus for every worthless rock?
And another suggestion regarding focus stealing. When I'm scrolling around the map, various events trigger a pause + jumping to the event location. But since I'm in the middle of moving, the focused location is immediately lost. I'd like to be able to scroll through the recent announcements and jump to the location where any message was triggered (such as a dead dwarf, an incoming caravan, a kobold thief spotted, etc.).
And finally I'd like to express my frustration with trying to navigate the build menu. It feels like everything just got dumped in there, and I'm constantly having to scroll through dozens of items trying to find the right one. A little organization would be nice. I don't expect this to be followed exactly, but something along these lines:
Furniture: Armor Stand, Bed, Seat, Burial Receptacle, Cabinet, Container, Door, Weapon Rack, Statue, Table, Cage, Glass Window, Gem Window, Well (maybe)
Structural: Everything in Wall/Floor/Stairs, Farm plot, Paved Road, Dirt Road, Bridge, Support, Floodgate, Floor Hatch, Wall Grate, Floor Grate, Vertical Bars, Floor Bars
Buildings:
Workshops menu, Furnaces menu, Kennel, Trade Depot, Seige engines menu, Machine components menu
Possibly put animal trap with traps
Oh, and it would be really convenient to designate certain weapons as practice weapons and other weapons for combat and automatically switch as needed.