I've combined your sugestions and make this little cheat that works with no problem.
My code:
On my .css file, I forced my to be like this:
textarea.ckeditor {
visibility: visible !important;
display: block !important;
height: 0px !important;
border: none !important;
resize:none;
overflow: hidden; }
And my .js validation is the normal format:
$("#submit-templateeditor").click(function(){
CKEDITOR.instances.templateeditor.updateElement();
$("#create-message-form-3").validate({
rules: {
templateeditor: "required"
},
messages: {
templateeditor: "Please add some code before continue"
},
errorPlacement: function(error, element){
$(element).each(function (){
$(this).parent('div').find('p.error').html(error);
});
}
});
});