Hi – thanks for your purchase. Sorry to hear you are having trouble. Looks like you are trying to replicate the demo site and want your installation to look like the theme preview site. Pls have a look at this video on how to do the same (includes revolution slider setup). It’s not difficult IMO and if you still have trouble, pls post a private message here with a login to your WP installation and I can help you out with the same. Thanks
Showcase slides are used in Nivo and Flex Sliders. Nivo Slider and Flex sliders exist just to provide a lightweight option to the users for sliders. Many users do not need the layering, animations and many other premium features that Revolution Slider provides. These features could be overkill for certain types of businesses(medical is one example) that are more information based and less creative in presentation. Flex or Nivo is easy to setup, responsive and perform well. Hope this helps.