All MuTools editors work in the same way. The pictures below use the Sequence Editor as an example, but it works everywhere the same.
Zooming Using The Mouse Wheel
Use the mouse-wheel to zoom in/out in the main direction. Zooming is focused on the cursor point.
Hold Alt and use the mouse-wheel to zoom in/out in the other direction. Zooming is focused on the cursor point.
Scrolling Using Ctrl + Mouse Wheel
Hold Ctrl and use the mouse-wheel to move the editor in its main direction.
Hold Ctrl+Alt and use the mouse-wheel to move the editor in its other direction.
Scrolling Using The Right Mouse Button
Right-click-drag to pan the editor. You can also use the middle mouse button for this.
Zooming Using Ctrl + Right Mouse Button
Hold Ctrl and right-click-drag to zoom in/out on the cursor point. You can also use the middle mouSe button for this.
User Preference: Switch Zoom <-> Scroll
Note that there is a preference called "EditorNavigation" with which you can reverse the zooming and panning actions.
Note that some editors can only be panned/zoomed horizontally or vertically. E.g. the Event List Editor is a pure vertical editor.