Let's say you are in a very good team,your champions are all countering the others and both teams got a good composition.
The other team sees you are stronger and dodges,wouldn't you be sad?
They can dodge even though they don't have a troll or an idiot.
I think voting doesn't make sense,you should be able to dodge but if you dodge a ranked que,your time penalty should be something like 20-40 minutes,so you dodge only if there is a real troll in game.
Or,let's go with your system in a slight diffrent way:
There's a report button near every user in Champ selection and if 3 or 4 player's click the same user's report button,chat log in champ selection is sent to Tribunal,player is accused and game is canceled.
That way you can't dodge without reporting someone,and if you report an innocent person you might get a penalty aand trolls get banned,good for everyone.