Tinymce if thats the one your referring to is included software from another company. I would assume that software is not compatible with any page declaration of rtl. We would have no control over that editor and how it operates. It is included and has a switch to turn it off basic or advanced.
If your talking about the vbulletin editor if your integrated with vbulletin that editor is well is made by another company and they would answer any questions about there editor and how it is suppose to operate.
well not really 3 main files rest are plugin code. tiny_mce.js is the file that has the html I beleive but as to what your going to edit I can not say. You can visit the tinymce site to see if they have any suggestions.