roles and lanes in ranked

I've heard about and had some people who were assign a role on a ranked game and wasn't planning even to play it, like "i picked support to reduce the queue time, now i gp top".

So I have an idea: Create a system that will check each player where he was assign and how he really played... If a player was assign support but trolled and went top it will send a massage to him in-game and will warn him, and if he won't listen to it he will be banned.

Now in the match up screen players will have the option to trade roles like trading champs so the system won't ban them if they were assign jg and went top with permission...

This way trollers that picked support and didnt play as one will get banned!

I believe this option will make people less troll and pick their planned roles.