I've noticed that progress between ranks drops after couple hours, but after I get new rank, it stays. Today my rank dropped to 1.
No - there is a bug I cannot find - if you enter the queue and decide to leave - your character will probably still play but you get -10 points as a leaver.
Ranks seem to be somewhat broken, mine is stuck at one, no matter how often I win.
Customer support service by UserEcho