No. To be able to show you the content the browser must generate the DOM that your html says, if the html isn't valid (missing closing tags, bad nesting, or like your other message just a <td> without a parent table and tr), then the browser will fix it however it likes.
FCKeditor relies on the browser to get the content that the user has created/changed, so if the browser changes your bad html then you must take care to provide a valid html.
RE: closing tags auto generated
To be able to show you the content the browser must generate the DOM that your html says, if the html isn't valid (missing closing tags, bad nesting, or like your other message just a <td> without a parent table and tr), then the browser will fix it however it likes.
FCKeditor relies on the browser to get the content that the user has created/changed, so if the browser changes your bad html then you must take care to provide a valid html.