Smurfing is not banable. Learn to deal with them. Accept the fact that they are here and bliz is ok with it. Only thing you can do is work with your team to dive the smurf then take out the rest of the team. Other thing you can do is unistall but, its better that you just work with your whole team. You cant 1v6 in overwatch unless the people you are playing against are god awful.
Nope i seen owl and t500 place gold and plat cause of bad players or other smurf stacks. If a t500 goes solo queue it is quite possilble to place that low.
Jeff himself said its not. Throwing is though. He said the system is designed to have them move up to were they belong quickly. Problem is they didnt taking into account throwers leaver toxic players and god awfull teammates that make it so the best players in the world cant even win a match.