Add "kodi.host = x.x.x.x" to your config, where x.x.x.x is the IP address (or hostname) or your Shield - that's all you need. You don't need to set the webserver username/password unless you've changed the defaults in Kodi.
Texture Cache Maintenance Utility: Preload your texture cache for optimal UI performance. Remotely manage media libraries. Purge unused artwork to free up space. Find missing media. Configurable QA check to highlight metadata issues. Aid in diagnosis of library and cache related problems.