The settings window has two parts. One for the animation preview and the x-sheet, one for the capturing module of eXposer.
Besides settings the general properties of your animation like resolution and frame rate, there is the merge mode, which will be Black + White = Black by default. This makes most sense for drawn frames, because you consider the white of the paper as transparent when merging levels. Grays inbetween will be semitransparent, of course. Black is fully opaque. If you put it to Black + White = Grey, all colors are treated equally, and true mixing takes place.
Default Cell Duration is the duration fo every frame that you drag from the source list into the x-sheet. Adjust it to your liking.
Magnify Preview enables you to "magnify" the animation preview. By default it is Off. If you want to see your animation bigger in the preview, set this to 150% or even 200%.
The controls on the Capture part have the following meaning: Width and Height control the format of the input video stream. On the right, you can set the upper left and lower right corner for cropping the video into a different size.
Tip: If you want to save the settings permanently for all new x-sheets, use the Save As Default button. You can still change the setting for every individual x-sheet document. They will be saved with the file and the settings in an x-sheet will always override the default settings.