is there any way that CMS will be creating another default pages like Home, Contact, AboutUs ??

for example i create StuffPage and i want that the CMS will automatically add a new Page Type to my StuffPage

- StuffPage
-- new Page Type add by CMS

off course you can, look how the blog module works:

	/**
	 * Create default blog setup
	 */
	function requireDefaultRecords() {
		parent::requireDefaultRecords();
		
		if(!DataObject::get_one('BlogHolder')) {
			$blogholder = new BlogHolder();
			$blogholder->Title = "Blog";
			$blogholder->URLSegment = "blog";
			$blogholder->Status = "Published";
			
			$widgetarea = new WidgetArea();
			$widgetarea->write();
			
			$blogholder->SideBarID = $widgetarea->ID;
			$blogholder->write();
			$blogholder->publish("Stage", "Live");
			
			$managementwidget = new BlogManagementWidget();
			$managementwidget->ParentID = $widgetarea->ID;
			$managementwidget->write();
			
			$tagcloudwidget = new TagCloudWidget();
			$tagcloudwidget->ParentID = $widgetarea->ID;
			$tagcloudwidget->write();
			
			$archivewidget = new ArchiveWidget();
			$archivewidget->ParentID = $widgetarea->ID;
			$archivewidget->write();
			
			$widgetarea->write();
			
			$blog = new BlogEntry();
			$blog->Title = _t('BlogHolder.SUCTITLE', "SilverStripe blog module successfully installed");
			$blog->URLSegment = 'sample-blog-entry';
			$blog->setDate(date("Y-m-d H:i:s",time()));
			$blog->Tags = _t('BlogHolder.SUCTAGS',"silverstripe, blog");
			$blog->Content = _t('BlogHolder.SUCCONTENT',"Congratulations, the SilverStripe blog module has been successfully installed. This blog entry can be safely deleted. You can configure aspects of your blog (such as the widgets displayed in the sidebar) in the CMS.");
			$blog->Status = "Published";
			$blog->ParentID = $blogholder->ID;
			$blog->write();
			$blog->publish("Stage", "Live");
			
			Database::alteration_message("Blog page created","created");
		}
	}