This is a list of what I personally feel requires more attention because they are gamebreakers.
I'm not saying they are not already known or under development, I simply state this here, regardless of the last 2 months I've passed on the forum and read many posts.
1) Mouse cursor refresh rate
Far too slow, requires to be ALWAYS on monitor frequency (60 Hz). This is done by drawing the pointer in hardware, not in the draw thread as it is done now.
2) Mouse pointer too small
On a 1680x1050 monitor it is too small, difficult to see when not moved. when it snows it's even worse.
3) Mouse camera mode
There should be an option to "lock" the camera mode without holding right mouse button (e.g. ALT key).
4) Mouse speed separated for x/y
Vertical movement seems to be too fast, horizontal too slow. It's slightly odd, but enough to get annoying. Let users calibrate this.
5) Mouse hover highlight
Many UI elements do not highlight, while things in the 3D world do. I think any active element in the UI should react when hovered.
6) Mouse tooltips
All icons (items, skills, actions, buttons, toolbar, whatever) should be described with tooltips. Especially skills should be explained and items detailed out (quality, weight, everything).
7) Mouse button uniformity
Activate items in the toolbar with number keys, lock them down (unmoveable) and have left-clicks activate them (right-clicks should open a menu to remove or pick up the item).
Pay close attention:
The "look and feel" of the UI is disappointingly awful and sloppy. It's impossible to move the mouse pointer fast and precise or to click fast. This means everything you try to do is greatly impeded by just this factor. It even gets so far that it is not enjoyable anymore to use the UI.