This has been mentioned before, but I just thought I would formally suggest this to riot:
Can you guys implement a vote kick option in the champion selection screen? There are multiple reasons as to why this will benefit and none that this will negatively impact the system.
1. If you have someone who is trolling/intentionally feeding, naturally you don't want them in your queue. This option will allow the remaining 4 players to remove the bad seed from the matchup and get another 5th player into their matchup.
2. If you have someone who is very stubborn and refuses to communicate with the team by, say, autolocking a mid champ despite there already being a mid hero, you can remove them to better suit the team comp. Players like that can only negatively affect your game with their selfishness. Nobody wants players like that on their team.
3. If you get a player who is afk or lagging really really bad and they autolock a champion at random, its going to seriously hurt your chances at winning. If the last pick is supposed to be jungle and you get, say, ezreal, the team is going to be at a serious handicap.
Mainly because of no.3, I also suggest that the person who is removed from queue initially only gets a short ban from matches, anywhere from 1-5 minutes. However, if this is done multiple times within a couple of hours or so, the ban should get extended as this is a sign the banned person may be trolling or doing something consistently bad to negatively affect the match they are in. Another thing I suggest, although this part is purely optional: people who offend multiple times in a short period of time should either have their pre-game chatlogs examined, or have an option in the vote/kick choice to choose why the person has been votekicked. This way, the people who are deliberately ruining gameplay get punished, and those who are lagging bad, afk, or just pick a champ that the rest don't agree with, but not intentionally trolling, can simply just be moved out without punishment.