I dont know if this got resolved, or if its written somewhere else but this is my FIX:

Use a:
HTMLText
TextareaField

Then in the CMS wrap your pasted code in:
<!-- MYcode -->
YOUR CODE HERE
<!--End MYcode-->

So for example my Rebel Mouse page this is my code:

RebelMousePage.php

<?php
class RebelMousePage extends Page {

	public static $db = array(
	'RebelMouseCode' => 'HTMLText'
	);


public function getCMSFields() {
        
        $fields = parent::getCMSFields(); 
		$fields->addFieldToTab('Root.RebelMouseCode', TextAreaField::create('RebelMouseCode','Paste Your Rebel Mouse Code Here: '));
		return $fields;         
    }   

}
class RebelMousePage_Controller extends Page_Controller {
}

And in the CMS:

<!-- RebelMouse -->
<script type="text/javascript" id="rebelmouse-embed-script" src="https://www.rebelmouse.com/static/js-build/embed/embed.js?site=USER&amp;height=1500&amp;flexible=1&amp;skip=about-site,show_rebelnav"></script><!--End RebelMouse-->

In the RebelMousePage.ss

$RebelMouseCode

hope this helps someone!

For the future - may be useful to someone

Use a:
- Text or Varchar

In CMSfield normaly like:
- new TextAreaField
- newTextField

In template
$NameField.RAW