How to access zoom options, e.g. to turn the mouse zooming on/off ?

From Plot->Chart Settings for Active Plot..., select the General tag, then select the Zoom tag as shown below.

The mouse zooming can be set from the Allow check box. Note that the “animated” setting will do the zooming in steps; this is a nice visual effect, but is not recommended on a slow PC. The Minimum pixels edit box determines the minimum size of the rectangle drawn by the mouse to obtain zooming (if the rectangle is smaller, no zooming will be performed). The Pen and Pattern buttons can be used to display the zoom rectangle area in different ways.