I found a solution to this problem. Tinymce maintains a list of characters it will convert, and you can override it:
entities : "60,lt,62,gt,38,amp,34,quot"
Doing that means only those entities are changed, and the other characters are stored in their unicode forms.
Text editors
Tinymce madness
Keskustelu on lukittu, joten et voi enää vastata siihen.