Selected answers from the Dumb SEO Questions Facebook & G+ community.
Yaser Arshad: Yes, if the URL is changed, it can cause to lose your ranking, but I disagree with Jeremy L. Knauff regarding the changing of title will result in losing of your ranking since I have always seen a boost in my websites when I changed the titles with insertion of proper KWs ofcourse.
Edit Yoast on my wordpress but NOT url part, can make me lose ranks? 
