I am also having this issue. Force_edge does not seem to work--in fact, it made the overworld view jerk around and force the mouse back into the center. I tried the other options as well: force locked up the main menu and would not allow the mouse out of center, disable and enable allowed regular mouse usage in the menus and overworld map, but not battles/city exploration.
I wonder, are you using virtual window alongside one of these settings?
Edit: A clarification. By creating a virtual window at the same resolution as the game, and using the force_edge registry edit, the game does work as expected in battles/towns, as well as menus. Moving the mouse to the edge of the overland map in order to rotate it will result in the mouse jerking towards the center. However, by holding the right mouse button and dragging left or right, the camera can be rotated without any issues. This seems like an acceptable work-around until a better solution arrives.