You should be able to add server validation and a server show if by using the binding for the form element that is created.
You can add client validation by adding the following to the ckeditor code:
$CKEditor_config["props"] = array();
$CKEditor_config["props"]["required"] = true;
$CKEditor_config["props"]["min"] = 20;
$CKEditor_config["props"]["max"] = 1000;
Min and max are optional but allow you to set a minimum and maximum length.