Put your js files under the 'js' folder in your custom skin folder, Pressero will include the file with your pages automatically.
CSS files: There is no automatic import for CSS files, we suggest you put CSS files inside of the 'CSS' folder. Pressero will include 'layout.css' from the root folder with your pages. So in the file 'layout.css', you can import CSS files using a method like "@import url(css/xxx.css)"
Keep 'useDefaultCSS' and 'useDefaultJS' as false, they are deprecated properties that are only used in old skins.