Hi Wing,
I just made the changes in my svn sandbox to allow configuring to use FCKeditor in Safari. Unfortuantely in my testing it does not work. The editor does render but it can't edit and doesn't display the current content when you try to edit existing content.
The changes will be in svn trunk by late tonight. The relevant new config settings with default values are:
<add key="ForceFCKToDegradeToTextAreaInSafari" value="true" />
<add key="ForceFCKToDegradeToTextAreaInOpera" value="true" />
<add key="ForceTinyMCEInSafari" value="false" />
<add key="ForceTinyMCEInOpera" value="true" />
So by default I'm forcing FCKeditor to degrade to textare since it doesn't work but you can change it if you want to try it.
I found that TinyMCE crashes Safari on my old mac.
Best,
Joe