Re: About matching with players you have blocked
Unless you play in master/predator lobbies where the number of queuing players is considerably lower compared do low and mid elos, then chances that you get the same teammate two times is very low if you just wait a couple of seconds before you press "ready" after you get out your last match.
The reason why its not a good idea to make it so you never get matched with blocked players is first of all that it can be abused to block out "bad" players, especially in higher elos where the player count is lower, like mentioned before. But also, we cant underestimate how such thing would affect the number of possible teams that can be formed among premade duos and solo Qs. Imagine if Player A blocks Player B who is premade with player C who blocks player D who blocks Player A who blocks Player E who blocks Player B..... With such "spider web" of un-doable teams, the queue time would possibly be considerably prolonged.