I mean from what I see there's no ground for a refugee claim. Any ongoing war in your home country is not a legitimate ground for it, it's a common misconception.
Registration date is the actual date when your marriage was officially registered. If there's substantial gap between these two dates, you can address it on the letter of the explanation.
Yes, you can. I have just replied to you in https://www.canadavisa.com/canada-immigration-discussion-board/threads/legally-seperated.876242/#post-11112013 :)