The ajax calls are not a problem. I know a bit of coding outside your extension is required but since it is based on CKEditor I have raised the issue on there forum but as it has your code wrapper on it they advise to seek support from you!
Can I get the editor to edit the content of a div? If not is there a autosize function that would work with the textarea the editor creates?
this way at least I can get around the limitation of trying to edit a div and have the textarea expand vertically with no scroll bar or bottom tag bar showing.