Hi rwoduzo,
1. You're right. The Elonex does not support languages in Word format very well. You might want to try converting your books into PDFs with Calibre. ( http://calibre-ebook.com/ )
2. Theres some discussion in the posts above about covers. You can buy them on-line, others have made their own.
3. Mine doesn't read rtf. Again the best thing is to convert them.
Hope this helps,
Jon 🙂