Clicking the small map should bring you to that point on the big map. You should be able to click on a character without the screen centering on them. Single-click select character, double-click center the map on that character, click and hold to change the character line up. This way you single-click to select a character and move them to another character because you did not change the map to be centered on the other character. In this game you will find yourself selecting a character and then panning the map to move them next to the other character. This is one of my biggest UI gripes.
The walk-able area for 2 story buildings is rather broken making it hard to select a target that is on a different floor than you. Even when the map clearly show them on your view screen, you can not target them. You have to move around the map or move the character. Path interrupted or target too far away is understandable, but a lot of times it is just errors with the walk-able terrain you see and are able to select. The cursor is on a floor that you do not see. The character will start walking to the other floor even though that is not visually what you clicked.
Those are the main two that I have found. I am sure there are more, but these are critical.
