Select either the rotate-only or the combined edit mode. 

Alternate 1:
Left click the mouse and drag the rotate axis line around. Under combined mode, hold the Command key while dragging the mouse.

The rotate line is anchored on the rotation center anchor point - the point in the image where the image is rotated around. The current rotation amount is shown in the bottom right corner of the image. This is the most precise alternative.

Alternate 2:
Use the rotate trackpad touch gesture to zoom in/out of the fractal.

How do i move the anchor point in rotate, zoom and combined edit modes?

The anchor point determines the point in the fractal that is either used to zoom the view in/out around or used to rotate the view around.

Left mouse click and drag the red anchor point to another spot. Use the Center button to re-center the anchor point in the window.

See Also

Edit View Camera Settings