Maybe something like this would work in your stylesheet:
* { cursor:pointer!important; }
I also suspect you might have to apply a rule like this within the style of the text editor's frame. You should read the documentation of the editor for instructions on how to do it.
Given that the WYSIWYG editor uses an <iframe> and an <iframe> is its own document, your CSS won't doesn't apply to the contents of the <iframe>.
When you use an <iframe> the resulting DOM structure looks a little like this...
<html>
<head>
<title>iframe example</title>
<link type="text/css" rel="stylesheet" href="outer.css" />
</head>
<body>
<div>
The contents of the outer document!
<iframe>
<html>
<head>
<title>iframe example</title>
<link type="text/css" rel="stylesheet" href="inner.css" />
</head>
<body>
<div>
The Contents of the iFrame!
</div>
</body>
</html>
</iframe>
</div>
</body>
</html>
... and the rules defined in outer.css don't apply to the contents of the <iframe>, and the contents of inner.css don't apply to the outer document.