I checked topic on which you were referring to. It has nothing to do with number of carousel items. You don’t need to change carousel image sizes, so revert that change. Only thing which you have to change is number of items inside carousel-init.js, so set values to 5 like on screenshot http://screencast.com/t/lAga6o00H1X4 , and carousel will display 5 images http://screencast.com/t/SXnUSKqEFmC
Of course, make sure that each post from selected category have featured image.