Photoshop PSD file(s) are included in Developer package if you need to do any customization work.
Each theme comes with the Themify framework which gives you complete customization of the style & functionality. See Features
Along with the framework, there are number of custom widgets that help you to display dynamic content. See widgets
All themes come with at least one skin which you can turn on/off instantly via our framework.
All members have access to documentation of our themes, framework, and widgets.
Theme members have access to our moderated support forums where you can disucss topics with other members or our team members.