CAN YOU 'GROUP' CHANGE SLIDE DURATIONS?	:)
Yes. Make all the settings you want on one slide in a slide show. Select that single slide with all the desired attributes in the "slideshow" tab of the project view window. In the edit menu you will find a "copy slide assets". Do that and then select all the other slides you need and under edit you can paste the attributes you want to the other slides. A menu should come up and allow you to select which attributes you want to copy. You can copy these attributes to any other slideshows you desire.
VERSION: N/A AND ALSO... SOURCE: Michael Cheney