New feature: while rotating the environment by dragging the mouse with the right mouse button pressed, temporarily center screen rotation on the mouse position by holding down the control key. Rotation would be centered on the current mouse position at the moment the key is pressed, until it is released.
Reason: Currently the environment always rotates around the center of the screen. Objects that are not at or near the center tend to get moved out of sight, especially when the view is zoomed in. Examining an object from all sides would be much easier if you could center the rotation on any point by holding down a key.