It's so frustrating. The help desk tries to be helpful but they just don't give you the info you need to resolve the problem. I'm sure they're mobbed. Did you actually get them to provide you with the actual error messages? Mine were pretty cryptic but one of them mentioned an image. The only image I had in the book was the cover. Like I said, once I removed it from the Scrivener compile, it uploaded fine.
Did you try putting your .epub file through a validator? That's helped me in past discover other errors. You can try this one at http://validator.idpf.org.
Or, the next thing I was going to try (if I hadn't gotten it to work) was downloading the iBooks Author app, importing my book into that, then try publishing from that. That might work for you since you have special characters and a few internal images.
Another option is to open it in Calibre (http://calibre-ebook.com). If it looks fine in Calibre, save it as a new file, then try uploading that.
Another choice might be to get a 3rd party to handle the upload for you.
I hope one of these options helps you. Good luck!
Elaine