The best UI ideas I can think of:
- Replacing the awful cursor with a more accurate one (Seriously, when using ranged, the arrow head doesn't exactly prove to be accurate).
- Replacing the Range Gauge (so it doesn't stand in the middle of the screen, and rather uses a aiming icon that's attached to a mouse (say the mouse cursor turns into a bullseye and the aim % (number) builds up.)
- Replacing the Action Gauge (so you can tell how long it will take by a timed horizontal gauge that's at the top of the screen. 20 pixel wide and 5 pixel height works)
- Having a movement image appear when you order your hearthling to move to that spot
- Possible path finding mode by shift + left clicking the target area.
- Possible "instant" action by shift + right clicking crops/stones/etc.
- Possible vision outlining/transparency when things are within your line of view (say you are standing 5 tiles away and there's a fox blocked by a rock, the line of view links up to the fox thus it is outlined).
- Alternative way to see hidden objects by holding alt, and it will show up temporarily until you let it go.
- Allow queuing up multiple food to eat when seated at the table, which highlights them.
- Allow auto adjusting movement speeds simply by hitting a button, rather than using ctrl + r. Holding this button increases the speed to the possible max speed.
- Reconfigure and allow players to configure how the hotkey buttons work (ctrl + r, Tab for inventory, etc.).
- Allow "minimizing" the hud and still show vital information, like combat and status buttons (inventory, equipment) but as a minimized icon.
If possible, you can redesign all the icons used for combat and actions... Some current ones might not make sense (as in a lift action's cursor but its using a chisel?!)