The theme has a large number of site specific configuration and customisation options (there were over one hundred and thirty-five on the last count). These necessarily appear in the theme source files but in order to make it easier to change them they have been collected together as PHP code in separate options files for each template or module (these files have names ending -options.php to make them easy to identify). To make things even easier the theme will exploit the Easy Theme Options plugin, if installed, to set these options without needing to touch the theme files at all.
Easy Theme Options adds a 'Theme Options' entry to the Appearance menu on the WordPress administrative menu. There are currently fourteen tabs in the Theme Options which correspond to the Global Options, the Navbar,the Links (URLs), the Slider, the Tabs, the Logos, the Boxes, the Pane, the Header, the Main Index, the Sidebar, the Footer and the 404 page, plus a 'Help' tab from the plugin itself.
The theme options are discussed in relation to the Easy Theme Options settings, but it must be emphasised that use of this plugin is optional and the same options can be set 'manually' in the options files. Please be aware that the colour options may show the same colour twice. This is because Easy Theme Options will use the first colour in a list as the default and so it is more convenient to add an extra entry that matches the default on top of a standard list of colours.
If you do find yourself needing to edit theme files it is recommended that you use a child theme. The theme has been designed to work with child themes, and indeed this site is using one.
Featured images on pages and posts are defined as part of the page creation process using the usual WordPress mechanisms. Images shown on the Slider are controlled by setting options in the Media Library.