The 'Graphics font' selection allows you to change both the font used in the graphics windows, and also the size of some graphics objects, for instance the dots at contour points and landmarks and the widths of contour lines.
The 'Icon size' selection allows you to select the size of all the icons. If set to 'auto', then the icon size will be determined by the size of the screen.
Selecting 'Use scrollbars when zooming' controls whether to show scrollbars in the image or 3D windows if they are zoomed such that not all of the data can be seen at once. If this is not selected, panning is only possible by using the right mouse button. Some graphics drivers do not work correctly with scrolled graphics windows and either display the image in the wrong location, or cause mouse clicks to be in the wrong location. In this case, disabling scrollbars should fix this issue.
All these settings are saved in your personal configuration file ('stradview.ini') so there is no need to reset them every time you launch Stradview.