It looks like the DataAssist code was added properly to the template derived pages. If the pages are not looking the way that you need them to you may want to try creating the DataAssist pages without a template so that you can get an idea for how the content on these pages is laid out. This should help you to understand how to craft your editable regions to work with the output that DA creates. This way your template page will be pre crafted to work with the DA forms and displays.
As for skinning PowerStore all of the css and design elements are exposed for you to edit, but there is not a tool or recommended approach for making these changes.
