I suspect just changing the mailout type won’t fix the character issue. Please check the collation of your posts table and let me know what it is so I can investigate further.
As for the positioning of the fields, I’ll see what I can do. I used to have jQuery moving them after the accounts fields, but in your case that was causing jQuery to raise an error and not render the fields (and the nonce security field). Because they weren’t rendered, the back-end check would die with the error you were seeing.
I’ll update this thread once I release the new, fixed version in case you still don’t see the updates.