In the message list, the "to" address of appears twice, when you open the message only once. This happened at least once, when I had an Email to write, added the address of the recipients, then deleted it by mistake, and then added it again.
It's not clear what you are talking about. Perhaps a screen shot will help to demonstrate?
Created attachment 2240 [details] Screenshot Message List
Created attachment 2241 [details] Screenshot Message View
Could you see what I meant?
Your screen shots don't reveal much. My guess is that you entered the address twice in the Compose window.