ShadowPlay works quite well with FFXIV and there is nothing special that needs to be done to make it work with FFXIV. All you need to do is start up the Geforce Experience application, click on the ShadowPlay tab and then flip the switch so it's on. Then select which mode you want to record in (automatic or manual) and then press Alt+F9 to start/stop recording. Remember that ShadowPlay is still in beta so it's rather feature gimped at the moment. As for the game scanning, that's not the ShadowPlay application, that's the Geforce Experience application scanning your system for compatible games to optimize.